diff --git a/app/lib/activitypub/activity/create.rb b/app/lib/activitypub/activity/create.rb
index b73c2cddd1..e5d431a528 100644
--- a/app/lib/activitypub/activity/create.rb
+++ b/app/lib/activitypub/activity/create.rb
@@ -146,6 +146,7 @@ class ActivityPub::Activity::Create < ActivityPub::Activity
     valid = !Admin::NgWord.reject?("#{@params[:spoiler_text]}\n#{@params[:text]}", uri: @params[:uri], target_type: :status, public: @status_parser.distributable_visibility?)
     valid = !Admin::NgWord.hashtag_reject?(@tags.size) if valid
     valid = !Admin::NgWord.mention_reject?(@mentions.count { |m| !m.silent }) if valid
+    valid = !Admin::NgWord.stranger_mention_reject_with_count?(@mentions.count { |m| !m.silent }) if valid && (mention_to_local_stranger? || reference_to_local_stranger?)
     valid = !Admin::NgWord.stranger_mention_reject?("#{@params[:spoiler_text]}\n#{@params[:text]}", uri: @params[:uri], target_type: :status, public: @status_parser.distributable_visibility?) if valid && (mention_to_local_stranger? || reference_to_local_stranger?)
 
     valid
diff --git a/app/models/admin/ng_word.rb b/app/models/admin/ng_word.rb
index c3d8c020a3..89230efc92 100644
--- a/app/models/admin/ng_word.rb
+++ b/app/models/admin/ng_word.rb
@@ -34,6 +34,14 @@ class Admin::NgWord
       mention_reject?(text.gsub(Account::MENTION_RE)&.count || 0)
     end
 
+    def stranger_mention_reject_with_count?(mention_count)
+      post_stranger_mentions_max.positive? && post_stranger_mentions_max < mention_count
+    end
+
+    def stranger_mention_reject_with_extractor?(text)
+      stranger_mention_reject_with_count?(text.gsub(Account::MENTION_RE)&.count || 0)
+    end
+
     private
 
     def include?(text, word)
@@ -62,6 +70,11 @@ class Admin::NgWord
       value.is_a?(Integer) && value.positive? ? value : 0
     end
 
+    def post_stranger_mentions_max
+      value = Setting.post_stranger_mentions_max
+      value.is_a?(Integer) && value.positive? ? value : 0
+    end
+
     def record!(type, text, keyword, options)
       return unless options[:uri] && options[:target_type]
       return if options.key?(:public) && !options.delete(:public)
diff --git a/app/models/form/admin_settings.rb b/app/models/form/admin_settings.rb
index 144bb1a2ec..2513023b6e 100644
--- a/app/models/form/admin_settings.rb
+++ b/app/models/form/admin_settings.rb
@@ -50,6 +50,7 @@ class Form::AdminSettings
     hide_local_users_for_anonymous
     post_hash_tags_max
     post_mentions_max
+    post_stranger_mentions_max
     sensitive_words
     sensitive_words_for_full
     authorized_fetch
@@ -71,6 +72,7 @@ class Form::AdminSettings
     backups_retention_period
     post_hash_tags_max
     post_mentions_max
+    post_stranger_mentions_max
     registrations_limit
     registrations_limit_per_day
     registrations_start_hour
diff --git a/app/services/activitypub/process_status_update_service.rb b/app/services/activitypub/process_status_update_service.rb
index 2549c44ed6..cc549b97e4 100644
--- a/app/services/activitypub/process_status_update_service.rb
+++ b/app/services/activitypub/process_status_update_service.rb
@@ -161,11 +161,16 @@ class ActivityPub::ProcessStatusUpdateService < BaseService
   end
 
   def valid_status?
-    !Admin::NgWord.reject?("#{@status_parser.spoiler_text}\n#{@status_parser.text}", uri: @status.uri, target_type: :status) && !Admin::NgWord.hashtag_reject?(@raw_tags.size) && !Admin::NgWord.mention_reject?(@raw_mentions.size)
+    valid = !Admin::NgWord.reject?("#{@status_parser.spoiler_text}\n#{@status_parser.text}", uri: @status.uri, target_type: :status)
+    valid = !Admin::NgWord.hashtag_reject?(@raw_tags.size) if valid
+
+    valid
   end
 
   def validate_status_mentions!
     raise AbortError if (mention_to_stranger? || reference_to_stranger?) && Admin::NgWord.stranger_mention_reject?("#{@status.spoiler_text}\n#{@status.text}", uri: @status.uri, target_type: :status)
+    raise AbortError if Admin::NgWord.mention_reject?(@raw_mentions.size)
+    raise AbortError if (mention_to_stranger? || reference_to_stranger?) && Admin::NgWord.stranger_mention_reject_with_count?(@raw_mentions.size)
   end
 
   def mention_to_stranger?
diff --git a/app/services/post_status_service.rb b/app/services/post_status_service.rb
index d0341f65b5..3c4eb9c12f 100644
--- a/app/services/post_status_service.rb
+++ b/app/services/post_status_service.rb
@@ -210,10 +210,11 @@ class PostStatusService < BaseService
   def validate_status!
     raise Mastodon::ValidationError, I18n.t('statuses.contains_ng_words') if Admin::NgWord.reject?("#{@options[:spoiler_text]}\n#{@options[:text]}")
     raise Mastodon::ValidationError, I18n.t('statuses.too_many_hashtags') if Admin::NgWord.hashtag_reject_with_extractor?(@text)
-    raise Mastodon::ValidationError, I18n.t('statuses.too_many_mentions') if Admin::NgWord.mention_reject_with_extractor?(@text)
   end
 
   def validate_status_mentions!
+    raise Mastodon::ValidationError, I18n.t('statuses.too_many_mentions') if Admin::NgWord.mention_reject_with_extractor?(@text)
+    raise Mastodon::ValidationError, I18n.t('statuses.too_many_mentions') if (mention_to_stranger? || reference_to_stranger?) && Admin::NgWord.stranger_mention_reject_with_extractor?(@text)
     raise Mastodon::ValidationError, I18n.t('statuses.contains_ng_words') if (mention_to_stranger? || reference_to_stranger?) && Setting.stranger_mention_from_local_ng && Admin::NgWord.stranger_mention_reject?("#{@options[:spoiler_text]}\n#{@options[:text]}")
   end
 
diff --git a/app/services/update_status_service.rb b/app/services/update_status_service.rb
index 59caf4c6bb..1393e7eefa 100644
--- a/app/services/update_status_service.rb
+++ b/app/services/update_status_service.rb
@@ -84,6 +84,7 @@ class UpdateStatusService < BaseService
     raise Mastodon::ValidationError, I18n.t('statuses.contains_ng_words') if Admin::NgWord.reject?("#{@options[:spoiler_text]}\n#{@options[:text]}")
     raise Mastodon::ValidationError, I18n.t('statuses.too_many_hashtags') if Admin::NgWord.hashtag_reject_with_extractor?(@options[:text] || '')
     raise Mastodon::ValidationError, I18n.t('statuses.too_many_mentions') if Admin::NgWord.mention_reject_with_extractor?(@options[:text] || '')
+    raise Mastodon::ValidationError, I18n.t('statuses.too_many_mentions') if (mention_to_stranger? || reference_to_stranger?) && Admin::NgWord.stranger_mention_reject_with_extractor?(@options[:text] || '')
   end
 
   def validate_status_mentions!
diff --git a/app/views/admin/ng_words/show.html.haml b/app/views/admin/ng_words/show.html.haml
index 5af34cb80a..d188a179c0 100644
--- a/app/views/admin/ng_words/show.html.haml
+++ b/app/views/admin/ng_words/show.html.haml
@@ -23,6 +23,9 @@
   .fields-group
     = f.input :post_hash_tags_max, wrapper: :with_label, as: :integer, label: t('admin.ng_words.post_hash_tags_max')
 
+  .fields-group
+    = f.input :post_stranger_mentions_max, wrapper: :with_label, as: :integer, label: t('admin.ng_words.post_stranger_mentions_max')
+
   .fields-group
     = f.input :post_mentions_max, wrapper: :with_label, as: :integer, label: t('admin.ng_words.post_mentions_max')
 
diff --git a/config/locales/en.yml b/config/locales/en.yml
index da88271252..ddb7b03869 100644
--- a/config/locales/en.yml
+++ b/config/locales/en.yml
@@ -649,6 +649,7 @@ en:
       keywords_hint: The first character of the line is "?". to use regular expressions
       post_hash_tags_max: Hash tags max for posts
       post_mentions_max: Mentions max for posts
+      post_stranger_mentions_max: 投稿に設定可能なメンションの最大数 (If the mentions include at least one person who is not a follower of yours)
       stranger_mention_from_local_ng: フォローしていないアカウントへのメンションのNGワードを、ローカルユーザーによる投稿にも適用する
       stranger_mention_from_local_ng_hint: サーバーの登録が承認制でない場合、あなたのサーバーにもスパムが入り込む可能性があります
       test_error: Testing is returned any errors
diff --git a/config/locales/ja.yml b/config/locales/ja.yml
index d5eccff6d5..2b87a13798 100644
--- a/config/locales/ja.yml
+++ b/config/locales/ja.yml
@@ -642,6 +642,7 @@ ja:
       keywords_hint: 行を「?」で始めると、正規表現が使えます
       post_hash_tags_max: 投稿に設定可能なハッシュタグの最大数
       post_mentions_max: 投稿に設定可能なメンションの最大数
+      post_stranger_mentions_max: 投稿に設定可能なメンションの最大数 (メンション先にフォロワー以外を1人でも含む場合)
       stranger_mention_from_local_ng: フォローしていないアカウントへのメンションのNGワードを、ローカルユーザーによる投稿にも適用する
       stranger_mention_from_local_ng_hint: サーバーの登録が承認制でない場合、あなたのサーバーにもスパムが入り込む可能性があります
       test_error: NGワードのテストに失敗しました。正規表現のミスが含まれているかもしれません
diff --git a/spec/lib/activitypub/activity/create_spec.rb b/spec/lib/activitypub/activity/create_spec.rb
index 53662d0bf4..d9a90d8b0b 100644
--- a/spec/lib/activitypub/activity/create_spec.rb
+++ b/spec/lib/activitypub/activity/create_spec.rb
@@ -2068,7 +2068,79 @@ RSpec.describe ActivityPub::Activity::Create do
       end
 
       context 'when mentions limit is set' do
-        let(:post_mentions_max) { 2 }
+        let(:post_mentions_max) { 3 }
+        let(:post_stranger_mentions_max) { 0 }
+        let(:custom_before) { true }
+        let(:mention_recipient_alice) { Fabricate(:account) }
+        let(:mention_recipient_bob) { Fabricate(:account) }
+        let(:mention_recipient_ohagi) { Fabricate(:account) }
+        let(:mention_recipient_ohagi_follow) { true }
+        let(:object_json) do
+          {
+            id: [ActivityPub::TagManager.instance.uri_for(sender), '#bar'].join,
+            type: 'Note',
+            content: 'Lorem ipsum',
+            tag: [
+              {
+                type: 'Mention',
+                href: ActivityPub::TagManager.instance.uri_for(mention_recipient_alice),
+              },
+              {
+                type: 'Mention',
+                href: ActivityPub::TagManager.instance.uri_for(mention_recipient_bob),
+              },
+              {
+                type: 'Mention',
+                href: ActivityPub::TagManager.instance.uri_for(mention_recipient_ohagi),
+              },
+            ],
+          }
+        end
+
+        before do
+          Form::AdminSettings.new(post_mentions_max: post_mentions_max, post_stranger_mentions_max: post_stranger_mentions_max).save
+
+          mention_recipient_alice.follow!(sender)
+          mention_recipient_bob.follow!(sender)
+          mention_recipient_ohagi.follow!(sender) if mention_recipient_ohagi_follow
+
+          subject.perform
+        end
+
+        context 'when limit is enough' do
+          it 'creates status' do
+            expect(sender.statuses.first).to_not be_nil
+          end
+        end
+
+        context 'when limit is over' do
+          let(:post_mentions_max) { 1 }
+
+          it 'creates status' do
+            expect(sender.statuses.first).to be_nil
+          end
+        end
+
+        context 'when limit for stranger is over but normal limit is not reach' do
+          let(:post_stranger_mentions_max) { 1 }
+
+          it 'creates status' do
+            expect(sender.statuses.first).to_not be_nil
+          end
+        end
+
+        context 'when limit for stranger is over and following partically' do
+          let(:post_stranger_mentions_max) { 1 }
+          let(:mention_recipient_ohagi_follow) { false }
+
+          it 'creates status' do
+            expect(sender.statuses.first).to be_nil
+          end
+        end
+      end
+
+      context 'when mentions limit for stranger is set' do
+        let(:post_stranger_mentions_max) { 2 }
         let(:custom_before) { true }
         let(:object_json) do
           {
@@ -2089,7 +2161,7 @@ RSpec.describe ActivityPub::Activity::Create do
         end
 
         before do
-          Form::AdminSettings.new(post_mentions_max: post_mentions_max).save
+          Form::AdminSettings.new(post_stranger_mentions_max: post_stranger_mentions_max).save
           subject.perform
         end
 
@@ -2100,7 +2172,7 @@ RSpec.describe ActivityPub::Activity::Create do
         end
 
         context 'when limit is over' do
-          let(:post_mentions_max) { 1 }
+          let(:post_stranger_mentions_max) { 1 }
 
           it 'creates status' do
             expect(sender.statuses.first).to be_nil
diff --git a/spec/services/post_status_service_spec.rb b/spec/services/post_status_service_spec.rb
index e7fa1a8ddf..d39d52ab9a 100644
--- a/spec/services/post_status_service_spec.rb
+++ b/spec/services/post_status_service_spec.rb
@@ -742,9 +742,11 @@ RSpec.describe PostStatusService, type: :service do
     end
 
     it 'using mentions under limit' do
-      Fabricate(:account, username: 'a')
-      Fabricate(:account, username: 'b')
+      a = Fabricate(:account, username: 'a')
+      b = Fabricate(:account, username: 'b')
       account = Fabricate(:account)
+      a.follow!(account)
+      b.follow!(account)
       text = '@a @b'
       Form::AdminSettings.new(post_mentions_max: 2).save
 
@@ -755,11 +757,64 @@ RSpec.describe PostStatusService, type: :service do
     end
 
     it 'using mentions over limit' do
+      a = Fabricate(:account, username: 'a')
+      b = Fabricate(:account, username: 'b')
+      account = Fabricate(:account)
+      a.follow!(account)
+      b.follow!(account)
+      text = '@a @b'
+      Form::AdminSettings.new(post_mentions_max: 1).save
+
+      expect { subject.call(account, text: text) }.to raise_error Mastodon::ValidationError
+    end
+
+    it 'using mentions for stranger under limit' do
       Fabricate(:account, username: 'a')
       Fabricate(:account, username: 'b')
       account = Fabricate(:account)
       text = '@a @b'
-      Form::AdminSettings.new(post_mentions_max: 1).save
+      Form::AdminSettings.new(post_stranger_mentions_max: 2).save
+
+      status = subject.call(account, text: text)
+
+      expect(status).to be_persisted
+      expect(status.text).to eq text
+    end
+
+    it 'using mentions for stranger over limit' do
+      Fabricate(:account, username: 'a')
+      Fabricate(:account, username: 'b')
+      account = Fabricate(:account)
+      text = '@a @b'
+      Form::AdminSettings.new(post_stranger_mentions_max: 1).save
+
+      expect { subject.call(account, text: text) }.to raise_error Mastodon::ValidationError
+    end
+
+    it 'using mentions for stranger over limit but normal setting is under limit' do
+      a = Fabricate(:account, username: 'a')
+      b = Fabricate(:account, username: 'b')
+      account = Fabricate(:account)
+      a.follow!(account)
+      b.follow!(account)
+      text = '@a @b'
+      Form::AdminSettings.new(post_mentions_max: 2, post_stranger_mentions_max: 1).save
+
+      status = subject.call(account, text: text)
+
+      expect(status).to be_persisted
+      expect(status.text).to eq text
+    end
+
+    it 'using mentions for stranger over limit but normal setting is under limit when following one only' do
+      a = Fabricate(:account, username: 'a')
+      b = Fabricate(:account, username: 'b')
+      Fabricate(:account, username: 'c')
+      account = Fabricate(:account)
+      a.follow!(account)
+      b.follow!(account)
+      text = '@a @b @c'
+      Form::AdminSettings.new(post_mentions_max: 3, post_stranger_mentions_max: 2).save
 
       expect { subject.call(account, text: text) }.to raise_error Mastodon::ValidationError
     end