diff --git a/app/views/application/_global_nav.slim b/app/views/application/_global_nav.slim
index f608ccf7f98..4cf1a68fc1d 100644
--- a/app/views/application/_global_nav.slim
+++ b/app/views/application/_global_nav.slim
@@ -68,4 +68,7 @@ nav.global-nav
             = link_to talks_link, class: "global-nav-links__link #{current_link(/talk/)}" do
               .global-nav-links__link-icon
                 i.fas.fa-comment-alt-smile
+              - if admin_or_mentor_login? && Talk.unreplied.count.positive?
+                .global-nav__item-count.a-notification-count.is-only-mentor
+                  = Talk.unreplied.count
               .global-nav-links__link-label 相談
diff --git a/app/views/talks/_tabs.html.slim b/app/views/talks/_tabs.html.slim
index cecd0ca3d8f..ea5daf6d622 100644
--- a/app/views/talks/_tabs.html.slim
+++ b/app/views/talks/_tabs.html.slim
@@ -6,3 +6,6 @@
       li.page-tabs__item
         = link_to talks_unreplied_index_path, class: "page-tabs__item-link #{current_link(/^talks-unreplied-index/)}" do
           | 未返信
+          - if admin_or_mentor_login? && Talk.unreplied.count.positive?
+            .page-tabs__item-count.a-notification-count
+              = Talk.unreplied.count
diff --git a/test/system/notification/talk_test.rb b/test/system/notification/talk_test.rb
index b45e68022dc..51b89d2f6f7 100644
--- a/test/system/notification/talk_test.rb
+++ b/test/system/notification/talk_test.rb
@@ -65,4 +65,29 @@ class Notification::TalkTest < ApplicationSystemTestCase
       assert_text 'komagataさんからコメントが届きました。'
     end
   end
+
+  test 'The number of unreplied comments is displayed in the global navigation and unreplied tab of the talks room' do
+    visit_with_auth '/talks/unreplied', 'komagata'
+    within(:css, '.global-nav') do
+      within(:css, "a[href='/talks']") do
+        assert_selector '.global-nav__item-count.a-notification-count.is-only-mentor', count: 1
+      end
+    end
+    assert_selector '.page-tabs__item-count.a-notification-count', count: 1
+
+    talk_id = users(:with_hyphen).talk.id
+    visit_with_auth "/talks/#{talk_id}", 'komagata'
+    within('.thread-comment-form__form') do
+      fill_in('new_comment[description]', with: 'test')
+    end
+    click_button 'コメントする'
+
+    visit '/talks/unreplied'
+    within(:css, '.global-nav') do
+      within(:css, "a[href='/talks'") do
+        assert_no_selector '.global-nav__item-count.a-notification-count.is-only-mentor'
+      end
+    end
+    assert_no_selector '.page-tabs__item-count.a-notification-count'
+  end
 end