diff --git a/public/podcasts/0.md b/public/podcasts/0.md
index b5525fef..f803bbe5 100644
--- a/public/podcasts/0.md
+++ b/public/podcasts/0.md
@@ -2,12 +2,12 @@
 
 <div class='episode-cover'>
   <a href=''
-     target='_blank' rel='noopenner'>
+     target='_blank'>
     <img src='/podcasts/0.png' alt='Cover Photo'>
   </a>
   <div class='btn-cover'>
-    <a class='btn-blue' href='' target='_blank' rel='noopenner'><i class='fa fa-youtube'></i> YouTube で聴く </a>
-    <a class='btn-blue' href='' target='_blank' rel='noopenner'><i class='fas fa-podcast'></i> Podcast で聴く </a>
+    <a class='btn-blue' href='' target='_blank'><i class='fa fa-youtube'></i> YouTube で聴く </a>
+    <a class='btn-blue' href='' target='_blank'><i class='fas fa-podcast'></i> Podcast で聴く </a>
   </div>
 </div>
 
diff --git a/public/podcasts/1.md b/public/podcasts/1.md
index ffcad66e..149cce48 100644
--- a/public/podcasts/1.md
+++ b/public/podcasts/1.md
@@ -2,12 +2,12 @@
 
 <div class='episode-cover'>
   <a href='https://www.youtube.com/watch?v=nL3xy9Xk8gM&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=1'
-     target='_blank' rel='noopenner'>
+     target='_blank'>
     <img src='/podcasts/1.png' alt='Cover Photo' class='lazy' loading='lazy'>
   </a>
   <div class='btn-cover'>
-    <a class='btn-blue' href='https://www.youtube.com/watch?v=nL3xy9Xk8gM&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=1' target='_blank' rel='noopenner'><i class='fa fa-youtube'></i> YouTube で聴く </a>
-    <a class='btn-blue' href='https://podcasters.spotify.com/pod/show/coderdojo-japan/episodes/001----CoderDojo-euhits' target='_blank' rel='noopenner'><i class='fas fa-podcast'></i> Podcast で聴く </a>
+    <a class='btn-blue' href='https://www.youtube.com/watch?v=nL3xy9Xk8gM&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=1' target='_blank'><i class='fa fa-youtube'></i> YouTube で聴く </a>
+    <a class='btn-blue' href='https://podcasters.spotify.com/pod/show/coderdojo-japan/episodes/001----CoderDojo-euhits' target='_blank'><i class='fas fa-podcast'></i> Podcast で聴く </a>
   </div>
 </div>
 
diff --git a/public/podcasts/10.md b/public/podcasts/10.md
index 12201152..e690ba83 100644
--- a/public/podcasts/10.md
+++ b/public/podcasts/10.md
@@ -12,12 +12,12 @@ For English speakers, <a href="https://twitter.com/CoderDojo/status/107567740441
 
 <div class='episode-cover'>
   <a href='https://www.youtube.com/watch?v=GhuhF0gngKo&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=10'
-     target='_blank' rel='noopenner'>
+     target='_blank'>
     <img src='/podcasts/10.png' alt='Cover Photo'>
   </a>
   <div class='btn-cover'>
-    <a class='btn-blue' href='https://www.youtube.com/watch?v=GhuhF0gngKo&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=10' target='_blank' rel='noopenner'><i class='fa fa-youtube'></i> YouTube で聴く </a>
-    <a class='btn-blue' href='https://podcasters.spotify.com/pod/show/coderdojo-japan/episodes/010---EN-Programming-is-Beyond-a-Job-For-Me-euhiuh' target='_blank' rel='noopenner'><i class='fas fa-podcast'></i> Podcast で聴く </a>
+    <a class='btn-blue' href='https://www.youtube.com/watch?v=GhuhF0gngKo&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=10' target='_blank'><i class='fa fa-youtube'></i> YouTube で聴く </a>
+    <a class='btn-blue' href='https://podcasters.spotify.com/pod/show/coderdojo-japan/episodes/010---EN-Programming-is-Beyond-a-Job-For-Me-euhiuh' target='_blank'><i class='fas fa-podcast'></i> Podcast で聴く </a>
   </div>
 </div>
 
diff --git a/public/podcasts/11.md b/public/podcasts/11.md
index c882f197..f02e2f53 100644
--- a/public/podcasts/11.md
+++ b/public/podcasts/11.md
@@ -2,12 +2,12 @@
 
 <div class='episode-cover'>
   <a href='https://www.youtube.com/watch?v=3tVJn5GqDtU&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=12'
-     target='_blank' rel='noopenner'>
+     target='_blank'>
     <img src='/podcasts/11.png' alt='Cover Photo'>
   </a>
   <div class='btn-cover'>
-    <a class='btn-blue' href='https://www.youtube.com/watch?v=3tVJn5GqDtU&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=12' target='_blank' rel='noopenner'><i class='fa fa-youtube'></i> YouTube で聴く </a>
-    <a class='btn-blue' href='https://podcasters.spotify.com/pod/show/coderdojo-japan/episodes/011---PR--with-euhiu6' target='_blank' rel='noopenner'><i class='fas fa-podcast'></i> Podcast で聴く </a>
+    <a class='btn-blue' href='https://www.youtube.com/watch?v=3tVJn5GqDtU&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=12' target='_blank'><i class='fa fa-youtube'></i> YouTube で聴く </a>
+    <a class='btn-blue' href='https://podcasters.spotify.com/pod/show/coderdojo-japan/episodes/011---PR--with-euhiu6' target='_blank'><i class='fas fa-podcast'></i> Podcast で聴く </a>
   </div>
 </div>
 
diff --git a/public/podcasts/12.md b/public/podcasts/12.md
index 71d3f9eb..c1877e80 100644
--- a/public/podcasts/12.md
+++ b/public/podcasts/12.md
@@ -4,12 +4,12 @@ Guest: [Bill Liao](https://twitter.com/liaonet), co-founder of [CoderDojo](https
 
 <div class='episode-cover'>
   <a href='https://www.youtube.com/watch?v=A8gENg7DPok&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=12'
-     target='_blank' rel='noopenner'>
+     target='_blank'>
     <img src='/podcasts/12.png' alt='Cover Photo'>
   </a>
   <div class='btn-cover'>
-    <a class='btn-blue' href='https://www.youtube.com/watch?v=A8gENg7DPok&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=12' target='_blank' rel='noopenner'><i class='fa fa-youtube'></i> YouTube で聴く </a>
-    <a class='btn-blue' href='https://podcasters.spotify.com/pod/show/coderdojo-japan/episodes/012---EN-The-1st-CoderDojo-and-the-Global-Vision-euhitq' target='_blank' rel='noopenner'><i class='fas fa-podcast'></i> Podcast で聴く </a>
+    <a class='btn-blue' href='https://www.youtube.com/watch?v=A8gENg7DPok&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=12' target='_blank'><i class='fa fa-youtube'></i> YouTube で聴く </a>
+    <a class='btn-blue' href='https://podcasters.spotify.com/pod/show/coderdojo-japan/episodes/012---EN-The-1st-CoderDojo-and-the-Global-Vision-euhitq' target='_blank'><i class='fas fa-podcast'></i> Podcast で聴く </a>
   </div>
 </div>
 
@@ -61,7 +61,7 @@ Guest: [Bill Liao](https://twitter.com/liaonet), co-founder of [CoderDojo](https
   Another thing in my dojo that works really well is we give out belts. You know, in karate you have a white belt, a red belt, a brown belt, green belt, you know, black belt. We have USB wristbands in white, in, you know, different colors. To get a black belt in my dojo, you need to have submitted code to GitHub that has been reused a million times. All right, so there have to be a million live instances of your code. That's a black belt. And the kids love the belts. They'll do a lot to earn the belt. And the belts are given free by businesses. They put their logo on there. That's fine. What else? Yeah, I guess the other thing is if you have questions, now's the time to ask. You know, if you want to know anything about CoderDojo, I still know pretty much everything. So thank you very much. And if you have questions, now's the time. Thank you very much.<br>
   <br>
   (※ 質疑応答に続きます。続きは
-  <a href='https://www.youtube.com/watch?v=KW8DW06f0cc&list=PL94GDfaSQTmK6xzLNsBMx8gkKrT2HiZ9D&index=5' target='_blank' rel='noopener'>YouTube</a>
+  <a href='https://www.youtube.com/watch?v=KW8DW06f0cc&list=PL94GDfaSQTmK6xzLNsBMx8gkKrT2HiZ9D&index=5' target='_blank'>YouTube</a>
   で!)
 </blockquote>
 
diff --git a/public/podcasts/13.md b/public/podcasts/13.md
index 6c09a904..17b707ca 100644
--- a/public/podcasts/13.md
+++ b/public/podcasts/13.md
@@ -5,12 +5,12 @@ CoderDojo Japan公式ブック Scratchでつくる!たのしむ!プログラミ
 
 <div class='episode-cover'>
   <a href='https://www.youtube.com/watch?v=Un_qJ2JzDAQ&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=13'
-     target='_blank' rel='noopenner'>
+     target='_blank'>
     <img src='/podcasts/13.png' alt='Cover Photo'>
   </a>
   <div class='btn-cover'>
-    <a class='btn-blue' href='https://www.youtube.com/watch?v=Un_qJ2JzDAQ&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=13' target='_blank' rel='noopenner'><i class='fa fa-youtube'></i> YouTube で聴く </a>
-    <a class='btn-blue' href='https://podcasters.spotify.com/pod/show/coderdojo-japan/episodes/013---CoderDojo--Scratch-euhiu2' target='_blank' rel='noopenner'><i class='fas fa-podcast'></i> Podcast で聴く </a>
+    <a class='btn-blue' href='https://www.youtube.com/watch?v=Un_qJ2JzDAQ&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=13' target='_blank'><i class='fa fa-youtube'></i> YouTube で聴く </a>
+    <a class='btn-blue' href='https://podcasters.spotify.com/pod/show/coderdojo-japan/episodes/013---CoderDojo--Scratch-euhiu2' target='_blank'><i class='fas fa-podcast'></i> Podcast で聴く </a>
   </div>
 </div>
 
diff --git a/public/podcasts/14.md b/public/podcasts/14.md
index 92d4520e..e6dfbbba 100644
--- a/public/podcasts/14.md
+++ b/public/podcasts/14.md
@@ -2,12 +2,12 @@ Makeblock 社 [@maming435](https://twitter.com/maming435) さんと CoderDojo 
 
 <div class='episode-cover'>
   <a href='https://www.youtube.com/watch?v=UbSd2qokAQg&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=14'
-     target='_blank' rel='noopenner'>
+     target='_blank'>
     <img src='/podcasts/14.png' alt='Cover Photo'>
   </a>
   <div class='btn-cover'>
-    <a class='btn-blue' href='https://www.youtube.com/watch?v=UbSd2qokAQg&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=14' target='_blank' rel='noopenner'><i class='fa fa-youtube'></i> YouTube で聴く </a>
-    <a class='btn-blue' href='https://podcasters.spotify.com/pod/show/coderdojo-japan/episodes/014---PR----Makeblock-euhitp' target='_blank' rel='noopenner'><i class='fas fa-podcast'></i> Podcast で聴く </a>
+    <a class='btn-blue' href='https://www.youtube.com/watch?v=UbSd2qokAQg&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=14' target='_blank'><i class='fa fa-youtube'></i> YouTube で聴く </a>
+    <a class='btn-blue' href='https://podcasters.spotify.com/pod/show/coderdojo-japan/episodes/014---PR----Makeblock-euhitp' target='_blank'><i class='fas fa-podcast'></i> Podcast で聴く </a>
   </div>
 </div>
 
diff --git a/public/podcasts/15.md b/public/podcasts/15.md
index 7b9ed812..3bf16946 100644
--- a/public/podcasts/15.md
+++ b/public/podcasts/15.md
@@ -5,12 +5,12 @@ DojoCon Japan 2019 - つぎのステップ
 
 <div class='episode-cover'>
   <a href='https://www.youtube.com/watch?v=uGTWCBIchKI&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=15'
-     target='_blank' rel='noopenner'>
+     target='_blank'>
     <img src='/podcasts/15.png' alt='Cover Photo'>
   </a>
   <div class='btn-cover'>
-    <a class='btn-blue' href='https://www.youtube.com/watch?v=uGTWCBIchKI&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=15' target='_blank' rel='noopenner'><i class='fa fa-youtube'></i> YouTube で聴く </a>
-    <a class='btn-blue' href='https://podcasters.spotify.com/pod/show/coderdojo-japan/episodes/015---DojoCon-Japan-2019-euhiu5' target='_blank' rel='noopenner'><i class='fas fa-podcast'></i> Podcast で聴く </a>
+    <a class='btn-blue' href='https://www.youtube.com/watch?v=uGTWCBIchKI&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=15' target='_blank'><i class='fa fa-youtube'></i> YouTube で聴く </a>
+    <a class='btn-blue' href='https://podcasters.spotify.com/pod/show/coderdojo-japan/episodes/015---DojoCon-Japan-2019-euhiu5' target='_blank'><i class='fas fa-podcast'></i> Podcast で聴く </a>
   </div>
 </div>
 
diff --git a/public/podcasts/16.md b/public/podcasts/16.md
index d0c5f54f..c9e99ade 100644
--- a/public/podcasts/16.md
+++ b/public/podcasts/16.md
@@ -5,12 +5,12 @@ DojoCon Japan 2019 - つぎのステップ
 
 <div class='episode-cover'>
   <a href='https://www.youtube.com/watch?v=um0CMoAX2aA&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=16'
-     target='_blank' rel='noopenner'>
+     target='_blank'>
     <img src='/podcasts/16.png' alt='Cover Photo'>
   </a>
   <div class='btn-cover'>
-    <a class='btn-blue' href='https://www.youtube.com/watch?v=um0CMoAX2aA&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=16' target='_blank' rel='noopenner'><i class='fa fa-youtube'></i> YouTube で聴く </a>
-    <a class='btn-blue' href='https://podcasters.spotify.com/pod/show/coderdojo-japan/episodes/016---DojoCon-Japan-2019-euhiu9' target='_blank' rel='noopenner'><i class='fas fa-podcast'></i> Podcast で聴く </a>
+    <a class='btn-blue' href='https://www.youtube.com/watch?v=um0CMoAX2aA&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=16' target='_blank'><i class='fa fa-youtube'></i> YouTube で聴く </a>
+    <a class='btn-blue' href='https://podcasters.spotify.com/pod/show/coderdojo-japan/episodes/016---DojoCon-Japan-2019-euhiu9' target='_blank'><i class='fas fa-podcast'></i> Podcast で聴く </a>
   </div>
 </div>
 
diff --git a/public/podcasts/17.md b/public/podcasts/17.md
index c814ecc7..6a1b341f 100644
--- a/public/podcasts/17.md
+++ b/public/podcasts/17.md
@@ -2,12 +2,12 @@
 
 <div class='episode-cover'>
   <a href='https://www.youtube.com/watch?v=EEcI-0O-1SA&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=17'
-     target='_blank' rel='noopenner'>
+     target='_blank'>
     <img src='/podcasts/17.png' alt='Cover Photo'>
   </a>
   <div class='btn-cover'>
-    <a class='btn-blue' href='https://www.youtube.com/watch?v=EEcI-0O-1SA&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=17' target='_blank' rel='noopenner'><i class='fa fa-youtube'></i> YouTube で聴く </a>
-    <a class='btn-blue' href='https://podcasters.spotify.com/pod/show/coderdojo-japan/episodes/017---euhiu8' target='_blank' rel='noopenner'><i class='fas fa-podcast'></i> Podcast で聴く </a>
+    <a class='btn-blue' href='https://www.youtube.com/watch?v=EEcI-0O-1SA&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=17' target='_blank'><i class='fa fa-youtube'></i> YouTube で聴く </a>
+    <a class='btn-blue' href='https://podcasters.spotify.com/pod/show/coderdojo-japan/episodes/017---euhiu8' target='_blank'><i class='fas fa-podcast'></i> Podcast で聴く </a>
   </div>
 </div>
 
diff --git a/public/podcasts/18.md b/public/podcasts/18.md
index a33c7e37..20eb59d0 100644
--- a/public/podcasts/18.md
+++ b/public/podcasts/18.md
@@ -4,12 +4,12 @@
 
 <div class='episode-cover'>
   <a href='https://www.youtube.com/watch?v=zmol3FhdL9U&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=18'
-     target='_blank' rel='noopenner'>
+     target='_blank'>
     <img src='/podcasts/18.png' alt='Cover Photo'>
   </a>
   <div class='btn-cover'>
-    <a class='btn-blue' href='https://www.youtube.com/watch?v=zmol3FhdL9U&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=18' target='_blank' rel='noopenner'><i class='fa fa-youtube'></i> YouTube で聴く </a>
-    <a class='btn-blue' href='https://podcasters.spotify.com/pod/show/coderdojo-japan/episodes/018----Scratch-euhiuf' target='_blank' rel='noopenner'><i class='fas fa-podcast'></i> Podcast で聴く </a>
+    <a class='btn-blue' href='https://www.youtube.com/watch?v=zmol3FhdL9U&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=18' target='_blank'><i class='fa fa-youtube'></i> YouTube で聴く </a>
+    <a class='btn-blue' href='https://podcasters.spotify.com/pod/show/coderdojo-japan/episodes/018----Scratch-euhiuf' target='_blank'><i class='fas fa-podcast'></i> Podcast で聴く </a>
   </div>
 </div>
 
diff --git a/public/podcasts/19.md b/public/podcasts/19.md
index 860b8d56..4d31b036 100644
--- a/public/podcasts/19.md
+++ b/public/podcasts/19.md
@@ -5,12 +5,12 @@
 
 <div class='episode-cover'>
   <a href='https://www.youtube.com/watch?v=fcIVHHeKQLQ&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=19'
-     target='_blank' rel='noopenner'>
+     target='_blank'>
     <img src='/podcasts/19.png' alt='Cover Photo'>
   </a>
   <div class='btn-cover'>
-    <a class='btn-blue' href='https://www.youtube.com/watch?v=fcIVHHeKQLQ&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=19' target='_blank' rel='noopenner'><i class='fa fa-youtube'></i> YouTube で聴く </a>
-    <a class='btn-blue' href='https://podcasters.spotify.com/pod/show/coderdojo-japan/episodes/019---CoderDojo-Japan-euhiu7' target='_blank' rel='noopenner'><i class='fas fa-podcast'></i> Podcast で聴く </a>
+    <a class='btn-blue' href='https://www.youtube.com/watch?v=fcIVHHeKQLQ&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=19' target='_blank'><i class='fa fa-youtube'></i> YouTube で聴く </a>
+    <a class='btn-blue' href='https://podcasters.spotify.com/pod/show/coderdojo-japan/episodes/019---CoderDojo-Japan-euhiu7' target='_blank'><i class='fas fa-podcast'></i> Podcast で聴く </a>
   </div>
 </div>
 
diff --git a/public/podcasts/2.md b/public/podcasts/2.md
index 87b03b85..5f4e5067 100644
--- a/public/podcasts/2.md
+++ b/public/podcasts/2.md
@@ -2,12 +2,12 @@
 
 <div class='episode-cover'>
   <a href='https://www.youtube.com/watch?v=mmZ5ZqoiViQ&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=2'
-     target='_blank' rel='noopenner'>
+     target='_blank'>
     <img src='/podcasts/2.png' alt='Cover Photo'>
   </a>
   <div class='btn-cover'>
-    <a class='btn-blue' href='https://www.youtube.com/watch?v=mmZ5ZqoiViQ&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=2' target='_blank' rel='noopenner'><i class='fa fa-youtube'></i> YouTube で聴く </a>
-    <a class='btn-blue' href='https://podcasters.spotify.com/pod/show/coderdojo-japan/episodes/002----CoderDojo--Scratch-euhiu1/a-a56juk1' target='_blank' rel='noopenner'><i class='fas fa-podcast'></i> Podcast で聴く </a>
+    <a class='btn-blue' href='https://www.youtube.com/watch?v=mmZ5ZqoiViQ&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=2' target='_blank'><i class='fa fa-youtube'></i> YouTube で聴く </a>
+    <a class='btn-blue' href='https://podcasters.spotify.com/pod/show/coderdojo-japan/episodes/002----CoderDojo--Scratch-euhiu1/a-a56juk1' target='_blank'><i class='fas fa-podcast'></i> Podcast で聴く </a>
   </div>
 </div>
 
diff --git a/public/podcasts/20.md b/public/podcasts/20.md
index b37c060d..b5145bea 100644
--- a/public/podcasts/20.md
+++ b/public/podcasts/20.md
@@ -2,12 +2,12 @@
 
 <div class='episode-cover'>
   <a href='https://www.youtube.com/watch?v=B6BZOhsu058&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=20'
-     target='_blank' rel='noopenner'>
+     target='_blank'>
     <img src='/podcasts/20.png' alt='Cover Photo'>
   </a>
   <div class='btn-cover'>
-    <a class='btn-blue' href='https://www.youtube.com/watch?v=B6BZOhsu058&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=20' target='_blank' rel='noopenner'><i class='fa fa-youtube'></i> YouTube で聴く </a>
-    <a class='btn-blue' href='https://podcasters.spotify.com/pod/show/coderdojo-japan/episodes/020---Scratch-euhitv' target='_blank' rel='noopenner'><i class='fas fa-podcast'></i> Podcast で聴く </a>
+    <a class='btn-blue' href='https://www.youtube.com/watch?v=B6BZOhsu058&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=20' target='_blank'><i class='fa fa-youtube'></i> YouTube で聴く </a>
+    <a class='btn-blue' href='https://podcasters.spotify.com/pod/show/coderdojo-japan/episodes/020---Scratch-euhitv' target='_blank'><i class='fas fa-podcast'></i> Podcast で聴く </a>
   </div>
 </div>
 
diff --git a/public/podcasts/21.md b/public/podcasts/21.md
index 50f5841c..82df7887 100644
--- a/public/podcasts/21.md
+++ b/public/podcasts/21.md
@@ -5,12 +5,12 @@ CoderDojo 向け TFabWork 無償レンタルプログラム
 
 <div class='episode-cover'>
   <a href='https://www.youtube.com/watch?v=43vUwn_M6Ro&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=21'
-     target='_blank' rel='noopenner'>
+     target='_blank'>
     <img src='/podcasts/21.jpg' alt='Cover Photo'>
   </a>
   <div class='btn-cover'>
-    <a class='btn-blue' href='https://www.youtube.com/watch?v=43vUwn_M6Ro&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=21' target='_blank' rel='noopenner'><i class='fa fa-youtube'></i> YouTube で聴く </a>
-    <a class='btn-blue' href='https://podcasters.spotify.com/pod/show/coderdojo-japan/episodes/021---TFabWorks-euhiv6' target='_blank' rel='noopenner'><i class='fas fa-podcast'></i> Podcast で聴く </a>
+    <a class='btn-blue' href='https://www.youtube.com/watch?v=43vUwn_M6Ro&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=21' target='_blank'><i class='fa fa-youtube'></i> YouTube で聴く </a>
+    <a class='btn-blue' href='https://podcasters.spotify.com/pod/show/coderdojo-japan/episodes/021---TFabWorks-euhiv6' target='_blank'><i class='fas fa-podcast'></i> Podcast で聴く </a>
   </div>
 </div>
 
diff --git a/public/podcasts/22.md b/public/podcasts/22.md
index af74d6ef..d84f6aac 100644
--- a/public/podcasts/22.md
+++ b/public/podcasts/22.md
@@ -2,12 +2,12 @@ DojoCon Japan 2020 共同実行委員長の曽我さん ([@ymsg19](https://twitt
 
 <div class='episode-cover'>
   <a href='https://www.youtube.com/watch?v=TsVtvvwKlKk&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=22'
-     target='_blank' rel='noopenner'>
+     target='_blank'>
     <img src='/podcasts/22.jpg' alt='Cover Photo'>
   </a>
   <div class='btn-cover'>
-    <a class='btn-blue' href='https://www.youtube.com/watch?v=TsVtvvwKlKk&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=22' target='_blank' rel='noopenner'><i class='fa fa-youtube'></i> YouTube で聴く </a>
-    <a class='btn-blue' href='https://podcasters.spotify.com/pod/show/coderdojo-japan/episodes/022---DojoCon-Japan-2020-euhiui' target='_blank' rel='noopenner'><i class='fas fa-podcast'></i> Podcast で聴く </a>
+    <a class='btn-blue' href='https://www.youtube.com/watch?v=TsVtvvwKlKk&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=22' target='_blank'><i class='fa fa-youtube'></i> YouTube で聴く </a>
+    <a class='btn-blue' href='https://podcasters.spotify.com/pod/show/coderdojo-japan/episodes/022---DojoCon-Japan-2020-euhiui' target='_blank'><i class='fas fa-podcast'></i> Podcast で聴く </a>
   </div>
 </div>
 
diff --git a/public/podcasts/23.md b/public/podcasts/23.md
index b1754f66..52c0580b 100644
--- a/public/podcasts/23.md
+++ b/public/podcasts/23.md
@@ -10,12 +10,12 @@ CoderDojo の活動を[計３０回以上](https://www.google.com/search?q=site%
 
 <div class='episode-cover'>
   <a href='https://www.youtube.com/watch?v=lzzo7-ieWjs&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=23'
-     target='_blank' rel='noopenner'>
+     target='_blank'>
     <img src='/podcasts/23.png' alt='Cover Photo'>
   </a>
   <div class='btn-cover'>
-    <a class='btn-blue' href='https://www.youtube.com/watch?v=lzzo7-ieWjs&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=23' target='_blank' rel='noopenner'><i class='fa fa-youtube'></i> YouTube で聴く </a>
-    <a class='btn-blue' href='https://podcasters.spotify.com/pod/show/coderdojo-japan/episodes/023----CoderDojo-euhitu' target='_blank' rel='noopenner'><i class='fas fa-podcast'></i> Podcast で聴く </a>
+    <a class='btn-blue' href='https://www.youtube.com/watch?v=lzzo7-ieWjs&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=23' target='_blank'><i class='fa fa-youtube'></i> YouTube で聴く </a>
+    <a class='btn-blue' href='https://podcasters.spotify.com/pod/show/coderdojo-japan/episodes/023----CoderDojo-euhitu' target='_blank'><i class='fas fa-podcast'></i> Podcast で聴く </a>
   </div>
 </div>
 
diff --git a/public/podcasts/24.md b/public/podcasts/24.md
index 609ae41d..d82705d5 100644
--- a/public/podcasts/24.md
+++ b/public/podcasts/24.md
@@ -2,12 +2,12 @@ CoderDojo 調布の [@jishiha](https://twitter.com/jishiha) さんより、2021
 
 <div class='episode-cover'>
   <a href='https://www.youtube.com/watch?v=Igm7lYTxkbc&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=24'
-     target='_blank' rel='noopenner'>
+     target='_blank'>
     <img src='/podcasts/24.jpg' alt='Cover Photo'>
   </a>
   <div class='btn-cover'>
-    <a class='btn-blue' href='https://www.youtube.com/watch?v=Igm7lYTxkbc&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=24' target='_blank' rel='noopenner'><i class='fa fa-youtube'></i> YouTube で聴く </a>
-    <a class='btn-blue' href='https://podcasters.spotify.com/pod/show/coderdojo-japan/episodes/024---Scratch-e16in4n' target='_blank' rel='noopenner'><i class='fas fa-podcast'></i> Podcast で聴く </a>
+    <a class='btn-blue' href='https://www.youtube.com/watch?v=Igm7lYTxkbc&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=24' target='_blank'><i class='fa fa-youtube'></i> YouTube で聴く </a>
+    <a class='btn-blue' href='https://podcasters.spotify.com/pod/show/coderdojo-japan/episodes/024---Scratch-e16in4n' target='_blank'><i class='fas fa-podcast'></i> Podcast で聴く </a>
   </div>
 </div>
 
diff --git a/public/podcasts/25.md b/public/podcasts/25.md
index c9cfc188..54a293eb 100644
--- a/public/podcasts/25.md
+++ b/public/podcasts/25.md
@@ -2,12 +2,12 @@
 
 <div class='episode-cover'>
   <a href='https://www.youtube.com/watch?v=cICEHEJxY_Y&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=25'
-     target='_blank' rel='noopenner'>
+     target='_blank'>
     <img src='/podcasts/25.png' alt='Cover Photo'>
   </a>
   <div class='btn-cover'>
-    <a class='btn-blue' href='https://www.youtube.com/watch?v=cICEHEJxY_Y&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=25' target='_blank' rel='noopenner'><i class='fa fa-youtube'></i> YouTube で聴く </a>
-    <a class='btn-blue' href='https://podcasters.spotify.com/pod/show/coderdojo-japan/episodes/025---222--CoderDojo2012-e1a8gp0' target='_blank' rel='noopenner'><i class='fas fa-podcast'></i> Podcast で聴く </a>
+    <a class='btn-blue' href='https://www.youtube.com/watch?v=cICEHEJxY_Y&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=25' target='_blank'><i class='fa fa-youtube'></i> YouTube で聴く </a>
+    <a class='btn-blue' href='https://podcasters.spotify.com/pod/show/coderdojo-japan/episodes/025---222--CoderDojo2012-e1a8gp0' target='_blank'><i class='fas fa-podcast'></i> Podcast で聴く </a>
   </div>
 </div>
 
diff --git a/public/podcasts/26.md b/public/podcasts/26.md
index 3dfa82a7..08c886a0 100644
--- a/public/podcasts/26.md
+++ b/public/podcasts/26.md
@@ -2,12 +2,12 @@
 
 <div class='episode-cover'>
   <a href='https://www.youtube.com/watch?v=xn5Y5OTvRZU&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=26'
-     target='_blank' rel='noopenner'>
+     target='_blank'>
     <img src='/podcasts/26.png' alt='Cover Photo'>
   </a>
   <div class='btn-cover'>
-    <a class='btn-blue' href='https://www.youtube.com/watch?v=xn5Y5OTvRZU&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=26' target='_blank' rel='noopenner'><i class='fa fa-youtube'></i> YouTube で聴く </a>
-    <a class='btn-blue' href='https://podcasters.spotify.com/pod/show/coderdojo-japan/episodes/026---CoderDojo-Japan-e1b340h' target='_blank' rel='noopenner'><i class='fas fa-podcast'></i> Podcast で聴く </a>
+    <a class='btn-blue' href='https://www.youtube.com/watch?v=xn5Y5OTvRZU&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=26' target='_blank'><i class='fa fa-youtube'></i> YouTube で聴く </a>
+    <a class='btn-blue' href='https://podcasters.spotify.com/pod/show/coderdojo-japan/episodes/026---CoderDojo-Japan-e1b340h' target='_blank'><i class='fas fa-podcast'></i> Podcast で聴く </a>
   </div>
 </div>
 
diff --git a/public/podcasts/27.md b/public/podcasts/27.md
index 8cb7f278..0d9654c9 100644
--- a/public/podcasts/27.md
+++ b/public/podcasts/27.md
@@ -2,12 +2,12 @@
 
 <div class='episode-cover'>
   <a href='https://www.youtube.com/watch?v=3r29apFGyGg&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=27'
-     target='_blank' rel='noopenner'>
+     target='_blank'>
     <img src='/podcasts/27.png' alt='Cover Photo'>
   </a>
   <div class='btn-cover'>
-    <a class='btn-blue' href='https://www.youtube.com/watch?v=3r29apFGyGg&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=27' target='_blank' rel='noopenner'><i class='fa fa-youtube'></i> YouTube で聴く </a>
-    <a class='btn-blue' href='https://podcasters.spotify.com/pod/show/coderdojo-japan/episodes/027---DojoCon-Japan-2021-e1j3gf1' target='_blank' rel='noopenner'><i class='fas fa-podcast'></i> Podcast で聴く </a>
+    <a class='btn-blue' href='https://www.youtube.com/watch?v=3r29apFGyGg&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=27' target='_blank'><i class='fa fa-youtube'></i> YouTube で聴く </a>
+    <a class='btn-blue' href='https://podcasters.spotify.com/pod/show/coderdojo-japan/episodes/027---DojoCon-Japan-2021-e1j3gf1' target='_blank'><i class='fas fa-podcast'></i> Podcast で聴く </a>
   </div>
 </div>
 
diff --git a/public/podcasts/28.md b/public/podcasts/28.md
index c3d9c407..50892ea5 100644
--- a/public/podcasts/28.md
+++ b/public/podcasts/28.md
@@ -5,12 +5,12 @@
 
 <div class='episode-cover'>
   <a href='https://www.youtube.com/watch?v=9OXt92jf0Dg&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=28'
-     target='_blank' rel='noopenner'>
+     target='_blank'>
     <img src='/podcasts/28.png' alt='Cover Photo'>
   </a>
   <div class='btn-cover'>
-    <a class='btn-blue' href='https://www.youtube.com/watch?v=9OXt92jf0Dg&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=28' target='_blank' rel='noopenner'><i class='fa fa-youtube'></i> YouTube で聴く </a>
-    <a class='btn-blue' href='https://podcasters.spotify.com/pod/show/coderdojo-japan/episodes/028---e1pa163' target='_blank' rel='noopenner'><i class='fas fa-podcast'></i> Podcast で聴く </a>
+    <a class='btn-blue' href='https://www.youtube.com/watch?v=9OXt92jf0Dg&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=28' target='_blank'><i class='fa fa-youtube'></i> YouTube で聴く </a>
+    <a class='btn-blue' href='https://podcasters.spotify.com/pod/show/coderdojo-japan/episodes/028---e1pa163' target='_blank'><i class='fas fa-podcast'></i> Podcast で聴く </a>
   </div>
 </div>
 
diff --git a/public/podcasts/29.md b/public/podcasts/29.md
index 1b7c81f1..6b4d9ded 100644
--- a/public/podcasts/29.md
+++ b/public/podcasts/29.md
@@ -2,12 +2,12 @@ DojoCon Japan 2022 の交流会で発表した『CoderDojo Japan 2022 活動報
 
 <div class='episode-cover'>
   <a href='https://www.youtube.com/watch?v=vydfLvxuVe4&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=29'
-     target='_blank' rel='noopenner'>
+     target='_blank'>
     <img src='/podcasts/29.png' alt='Cover Photo'>
   </a>
   <div class='btn-cover'>
-    <a class='btn-blue' href='https://www.youtube.com/watch?v=vydfLvxuVe4&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=29' target='_blank' rel='noopenner'><i class='fa fa-youtube'></i> YouTube で聴く </a>
-    <a class='btn-blue' href='https://podcasters.spotify.com/pod/show/coderdojo-japan/episodes/029---CoderDojo-Japan-2022-e1s49f0' target='_blank' rel='noopenner'><i class='fas fa-podcast'></i> Podcast で聴く </a>
+    <a class='btn-blue' href='https://www.youtube.com/watch?v=vydfLvxuVe4&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=29' target='_blank'><i class='fa fa-youtube'></i> YouTube で聴く </a>
+    <a class='btn-blue' href='https://podcasters.spotify.com/pod/show/coderdojo-japan/episodes/029---CoderDojo-Japan-2022-e1s49f0' target='_blank'><i class='fas fa-podcast'></i> Podcast で聴く </a>
   </div>
 </div>
 
diff --git a/public/podcasts/3.md b/public/podcasts/3.md
index 982d2e77..8ff2e8b3 100644
--- a/public/podcasts/3.md
+++ b/public/podcasts/3.md
@@ -2,12 +2,12 @@
 
 <div class='episode-cover'>
   <a href='https://www.youtube.com/watch?v=xQxg-TwVlWo&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=3'
-     target='_blank' rel='noopenner'>
+     target='_blank'>
     <img src='/podcasts/3.png' alt='Cover Photo'>
   </a>
   <div class='btn-cover'>
-    <a class='btn-blue' href='https://www.youtube.com/watch?v=xQxg-TwVlWo&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=3' target='_blank' rel='noopenner'><i class='fa fa-youtube'></i> YouTube で聴く </a>
-    <a class='btn-blue' href='https://podcasters.spotify.com/pod/show/coderdojo-japan/episodes/003----CoderDojo-euhiue' target='_blank' rel='noopenner'><i class='fas fa-podcast'></i> Podcast で聴く </a>
+    <a class='btn-blue' href='https://www.youtube.com/watch?v=xQxg-TwVlWo&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=3' target='_blank'><i class='fa fa-youtube'></i> YouTube で聴く </a>
+    <a class='btn-blue' href='https://podcasters.spotify.com/pod/show/coderdojo-japan/episodes/003----CoderDojo-euhiue' target='_blank'><i class='fas fa-podcast'></i> Podcast で聴く </a>
   </div>
 </div>
 
diff --git a/public/podcasts/30.md b/public/podcasts/30.md
index 83363fc9..b8eedbdb 100644
--- a/public/podcasts/30.md
+++ b/public/podcasts/30.md
@@ -2,12 +2,12 @@
 
 <div class='episode-cover'>
   <a href='https://www.youtube.com/watch?v=j4Us2yBqT2k&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=30'
-     target='_blank' rel='noopenner'>
+     target='_blank'>
     <img src='/podcasts/30.png' alt='Cover Photo'>
   </a>
   <div class='btn-cover'>
-    <a class='btn-blue' href='https://www.youtube.com/watch?v=j4Us2yBqT2k&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=30' target='_blank' rel='noopenner'><i class='fa fa-youtube'></i> YouTube で聴く </a>
-    <a class='btn-blue' href='https://podcasters.spotify.com/pod/show/coderdojo-japan/episodes/030---Microbit---CoderDojo-e1s61rm' target='_blank' rel='noopenner'><i class='fas fa-podcast'></i> Podcast で聴く </a>
+    <a class='btn-blue' href='https://www.youtube.com/watch?v=j4Us2yBqT2k&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=30' target='_blank'><i class='fa fa-youtube'></i> YouTube で聴く </a>
+    <a class='btn-blue' href='https://podcasters.spotify.com/pod/show/coderdojo-japan/episodes/030---Microbit---CoderDojo-e1s61rm' target='_blank'><i class='fas fa-podcast'></i> Podcast で聴く </a>
   </div>
 </div>
 
diff --git a/public/podcasts/31.md b/public/podcasts/31.md
index 5287f96e..b5e9e745 100644
--- a/public/podcasts/31.md
+++ b/public/podcasts/31.md
@@ -2,12 +2,12 @@
 
 <div class='episode-cover'>
   <a href='https://www.youtube.com/watch?v=gzgk8GDXSYc&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=31'
-     target='_blank' rel='noopenner'>
+     target='_blank'>
     <img src='/podcasts/31.png' alt='Cover Photo'>
   </a>
   <div class='btn-cover'>
-    <a class='btn-blue' href='https://www.youtube.com/watch?v=gzgk8GDXSYc&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=31' target='_blank' rel='noopenner'><i class='fa fa-youtube'></i> YouTube で聴く </a>
-    <a class='btn-blue' href='https://creators.spotify.com/pod/show/coderdojo-japan/episodes/031-----CoderDojo-Japan-e2u35h2' target='_blank' rel='noopenner'><i class='fas fa-podcast'></i> Podcast で聴く </a>
+    <a class='btn-blue' href='https://www.youtube.com/watch?v=gzgk8GDXSYc&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=31' target='_blank'><i class='fa fa-youtube'></i> YouTube で聴く </a>
+    <a class='btn-blue' href='https://creators.spotify.com/pod/show/coderdojo-japan/episodes/031-----CoderDojo-Japan-e2u35h2' target='_blank'><i class='fas fa-podcast'></i> Podcast で聴く </a>
   </div>
 </div>
 
diff --git a/public/podcasts/32.md b/public/podcasts/32.md
index f85a4f11..b850fc96 100644
--- a/public/podcasts/32.md
+++ b/public/podcasts/32.md
@@ -2,7 +2,7 @@
 
 <div class='episode-cover'>
   <a href='https://www.youtube.com/watch?v=Dd9IYiF0R6E&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=32'
-     target='_blank' rel='noopenner'>
+     target='_blank'>
     <img src='/podcasts/32.png' alt='Cover Photo'>
   </a>
   <div class='btn-cover'>
diff --git a/public/podcasts/33.md b/public/podcasts/33.md
index 95f3d73a..5fad69f5 100644
--- a/public/podcasts/33.md
+++ b/public/podcasts/33.md
@@ -3,7 +3,7 @@ DojoCon Japan 2025 の基調講演「**[プログラミング教育の脱構築
 
 <div class='episode-cover'>
   <a href='https://www.youtube.com/watch?v=hVRxM12xHeY&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU'
-     target='_blank' rel='noopenner'>
+     target='_blank'>
     <img src='/podcasts/33.webp' alt='Cover Photo'>
   </a>
   <div class='btn-cover'>
diff --git a/public/podcasts/34.md b/public/podcasts/34.md
index a22e2608..e8a7cd54 100644
--- a/public/podcasts/34.md
+++ b/public/podcasts/34.md
@@ -2,7 +2,7 @@
 
 <div class='episode-cover'>
   <a href='https://www.youtube.com/watch?v=ThOprvWsqkw&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU'
-     target='_blank' rel='noopenner'>
+     target='_blank'>
     <img src='/podcasts/34.png' alt='Cover Photo'>
   </a>
   <div class='btn-cover'>
diff --git a/public/podcasts/4.md b/public/podcasts/4.md
index 022f7d5f..d6543771 100644
--- a/public/podcasts/4.md
+++ b/public/podcasts/4.md
@@ -2,12 +2,12 @@
 
 <div class='episode-cover'>
   <a href='https://www.youtube.com/watch?v=sT5J3NkOXSk&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=4'
-     target='_blank' rel='noopenner'>
+     target='_blank'>
     <img src='/podcasts/4.png' alt='Cover Photo'>
   </a>
   <div class='btn-cover'>
-    <a class='btn-blue' href='https://www.youtube.com/watch?v=sT5J3NkOXSk&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=4' target='_blank' rel='noopenner'><i class='fa fa-youtube'></i> YouTube で聴く </a>
-    <a class='btn-blue' href='https://podcasters.spotify.com/pod/show/coderdojo-japan/episodes/004---DojoCon-Japan-euhiuc' target='_blank' rel='noopenner'><i class='fas fa-podcast'></i> Podcast で聴く </a>
+    <a class='btn-blue' href='https://www.youtube.com/watch?v=sT5J3NkOXSk&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=4' target='_blank'><i class='fa fa-youtube'></i> YouTube で聴く </a>
+    <a class='btn-blue' href='https://podcasters.spotify.com/pod/show/coderdojo-japan/episodes/004---DojoCon-Japan-euhiuc' target='_blank'><i class='fas fa-podcast'></i> Podcast で聴く </a>
   </div>
 </div>
 
diff --git a/public/podcasts/5.md b/public/podcasts/5.md
index 6a945d13..b19534ff 100644
--- a/public/podcasts/5.md
+++ b/public/podcasts/5.md
@@ -2,12 +2,12 @@
 
 <div class='episode-cover'>
   <a href='https://www.youtube.com/watch?v=aMyXinLDajs&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=5'
-     target='_blank' rel='noopenner'>
+     target='_blank'>
     <img src='/podcasts/5.png' alt='Cover Photo'>
   </a>
   <div class='btn-cover'>
-    <a class='btn-blue' href='https://www.youtube.com/watch?v=aMyXinLDajs&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=5' target='_blank' rel='noopenner'><i class='fa fa-youtube'></i> YouTube で聴く </a>
-    <a class='btn-blue' href='https://podcasters.spotify.com/pod/show/coderdojo-japan/episodes/005---DecaDojo-euhiu3' target='_blank' rel='noopenner'><i class='fas fa-podcast'></i> Podcast で聴く </a>
+    <a class='btn-blue' href='https://www.youtube.com/watch?v=aMyXinLDajs&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=5' target='_blank'><i class='fa fa-youtube'></i> YouTube で聴く </a>
+    <a class='btn-blue' href='https://podcasters.spotify.com/pod/show/coderdojo-japan/episodes/005---DecaDojo-euhiu3' target='_blank'><i class='fas fa-podcast'></i> Podcast で聴く </a>
   </div>
 </div>
 
diff --git a/public/podcasts/6.md b/public/podcasts/6.md
index c1980656..a50bc070 100644
--- a/public/podcasts/6.md
+++ b/public/podcasts/6.md
@@ -2,12 +2,12 @@
 
 <div class='episode-cover'>
   <a href='https://www.youtube.com/watch?v=6PlvxjocAs4&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=6'
-     target='_blank' rel='noopenner'>
+     target='_blank'>
     <img src='/podcasts/6.png' alt='Cover Photo'>
   </a>
   <div class='btn-cover'>
-    <a class='btn-blue' href='https://www.youtube.com/watch?v=6PlvxjocAs4&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=6' target='_blank' rel='noopenner'><i class='fa fa-youtube'></i> YouTube で聴く </a>
-    <a class='btn-blue' href='https://podcasters.spotify.com/pod/show/coderdojo-japan/episodes/006---PR-euhitt' target='_blank' rel='noopenner'><i class='fas fa-podcast'></i> Podcast で聴く </a>
+    <a class='btn-blue' href='https://www.youtube.com/watch?v=6PlvxjocAs4&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=6' target='_blank'><i class='fa fa-youtube'></i> YouTube で聴く </a>
+    <a class='btn-blue' href='https://podcasters.spotify.com/pod/show/coderdojo-japan/episodes/006---PR-euhitt' target='_blank'><i class='fas fa-podcast'></i> Podcast で聴く </a>
   </div>
 </div>
 
diff --git a/public/podcasts/7.md b/public/podcasts/7.md
index b074553c..fcfc9657 100644
--- a/public/podcasts/7.md
+++ b/public/podcasts/7.md
@@ -2,12 +2,12 @@ CoderDojo Kanazawa の寺本さん ([@teramotodaiki](https://twitter.com/teramot
 
 <div class='episode-cover'>
   <a href='https://www.youtube.com/watch?v=Pypw1lXb-XY&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=7'
-     target='_blank' rel='noopenner'>
+     target='_blank'>
     <img src='/podcasts/7.png' alt='Cover Photo'>
   </a>
   <div class='btn-cover'>
-    <a class='btn-blue' href='https://www.youtube.com/watch?v=Pypw1lXb-XY&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=7' target='_blank' rel='noopenner'><i class='fa fa-youtube'></i> YouTube で聴く </a>
-    <a class='btn-blue' href='https://podcasters.spotify.com/pod/show/coderdojo-japan/episodes/007---Hack-for-Dojo-euhiv4' target='_blank' rel='noopenner'><i class='fas fa-podcast'></i> Podcast で聴く </a>
+    <a class='btn-blue' href='https://www.youtube.com/watch?v=Pypw1lXb-XY&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=7' target='_blank'><i class='fa fa-youtube'></i> YouTube で聴く </a>
+    <a class='btn-blue' href='https://podcasters.spotify.com/pod/show/coderdojo-japan/episodes/007---Hack-for-Dojo-euhiv4' target='_blank'><i class='fas fa-podcast'></i> Podcast で聴く </a>
   </div>
 </div>
 
diff --git a/public/podcasts/8.md b/public/podcasts/8.md
index e93545d3..18d16bdd 100644
--- a/public/podcasts/8.md
+++ b/public/podcasts/8.md
@@ -2,12 +2,12 @@
 
 <div class='episode-cover'>
   <a href='https://www.youtube.com/watch?v=4T1kRlGPHwQ&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=8'
-     target='_blank' rel='noopenner'>
+     target='_blank'>
     <img src='/podcasts/8.png' alt='Cover Photo'>
   </a>
   <div class='btn-cover'>
-    <a class='btn-blue' href='https://www.youtube.com/watch?v=4T1kRlGPHwQ&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=8' target='_blank' rel='noopenner'><i class='fa fa-youtube'></i> YouTube で聴く </a>
-    <a class='btn-blue' href='https://podcasters.spotify.com/pod/show/coderdojo-japan/episodes/008---PR--CASE-Shinjuku-euhiun' target='_blank' rel='noopenner'><i class='fas fa-podcast'></i> Podcast で聴く </a>
+    <a class='btn-blue' href='https://www.youtube.com/watch?v=4T1kRlGPHwQ&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=8' target='_blank'><i class='fa fa-youtube'></i> YouTube で聴く </a>
+    <a class='btn-blue' href='https://podcasters.spotify.com/pod/show/coderdojo-japan/episodes/008---PR--CASE-Shinjuku-euhiun' target='_blank'><i class='fas fa-podcast'></i> Podcast で聴く </a>
   </div>
 </div>
 
diff --git a/public/podcasts/9.md b/public/podcasts/9.md
index 19167a56..d4e0111f 100644
--- a/public/podcasts/9.md
+++ b/public/podcasts/9.md
@@ -5,12 +5,12 @@ DojoBudokai 2017 - CoderDojo 広島
 
 <div class='episode-cover'>
   <a href='https://www.youtube.com/watch?v=c9CZqYjTDGw&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=9'
-     target='_blank' rel='noopenner'>
+     target='_blank'>
     <img src='/podcasts/9.png' alt='Cover Photo'>
   </a>
   <div class='btn-cover'>
-    <a class='btn-blue' href='https://www.youtube.com/watch?v=c9CZqYjTDGw&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=9' target='_blank' rel='noopenner'><i class='fa fa-youtube'></i> YouTube で聴く </a>
-    <a class='btn-blue' href='https://podcasters.spotify.com/pod/show/coderdojo-japan/episodes/009----CoderDojo-euhiuo' target='_blank' rel='noopenner'><i class='fas fa-podcast'></i> Podcast で聴く </a>
+    <a class='btn-blue' href='https://www.youtube.com/watch?v=c9CZqYjTDGw&list=PL94GDfaSQTmJxxnapafkApHYgQUJ6ABUU&index=9' target='_blank'><i class='fa fa-youtube'></i> YouTube で聴く </a>
+    <a class='btn-blue' href='https://podcasters.spotify.com/pod/show/coderdojo-japan/episodes/009----CoderDojo-euhiuo' target='_blank'><i class='fas fa-podcast'></i> Podcast で聴く </a>
   </div>
 </div>