diff --git a/app/controllers/statuses_controller.rb b/app/controllers/statuses_controller.rb
index be87161cc8..c375afc913 100644
--- a/app/controllers/statuses_controller.rb
+++ b/app/controllers/statuses_controller.rb
@@ -79,13 +79,9 @@ class StatusesController < ApplicationController
     @misskey_software = false
 
     return false if !@status.local? || signed_request_account&.domain.blank? || !@status.sending_maybe_compromised_privacy?
-
     return @misskey_software = true if DomainBlock.detect_invalid_subscription?(signed_request_account.domain)
 
-    info = InstanceInfo.find_by(domain: signed_request_account.domain)
-    return false if info.nil?
-
-    @misskey_software = %w(misskey calckey cherrypick sharkey).include?(info.software)
+    @misskey_software = InstanceInfo.invalid_subscription_software?(signed_request_account.domain)
   end
 
   def status_activity_serializer
diff --git a/app/helpers/follow_helper.rb b/app/helpers/follow_helper.rb
index d7d7ff35e9..a02e2a8832 100644
--- a/app/helpers/follow_helper.rb
+++ b/app/helpers/follow_helper.rb
@@ -27,9 +27,6 @@ module FollowHelper
   def proxyable_software?(account)
     return false if account.local?
 
-    info = InstanceInfo.find_by(domain: account.domain)
-    return false if info.nil?
-
-    %w(misskey calckey firefish meisskey cherrypick sharkey).include?(info.software)
+    InstanceInfo.proxy_account_software?(account.domain)
   end
 end
diff --git a/app/lib/account_statuses_filter.rb b/app/lib/account_statuses_filter.rb
index f97d9def3e..a14c943d01 100644
--- a/app/lib/account_statuses_filter.rb
+++ b/app/lib/account_statuses_filter.rb
@@ -161,14 +161,7 @@ class AccountStatusesFilter
 
   def misskey_software?
     return false if @account.nil? || @account.local?
-    return false if instance_info.nil?
 
-    %w(misskey cherrypick).include?(instance_info.software)
-  end
-
-  def instance_info
-    return @instance_info if defined?(@instance_info)
-
-    @instance_info = InstanceInfo.find_by(domain: @account.domain)
+    InstanceInfo.invalid_subscription_software?(@account.domain)
   end
 end
diff --git a/app/lib/activitypub/parser/status_parser.rb b/app/lib/activitypub/parser/status_parser.rb
index e982a12e63..a2ae658874 100644
--- a/app/lib/activitypub/parser/status_parser.rb
+++ b/app/lib/activitypub/parser/status_parser.rb
@@ -103,7 +103,7 @@ class ActivityPub::Parser::StatusParser
     return from_audience if from_audience
     return nil if default_searchability_from_bio?
 
-    searchability_from_bio || (misskey_software? ? misskey_searchability : nil)
+    searchability_from_bio || (invalid_subscription_software? ? misskey_searchability : nil)
   end
 
   def limited_scope
@@ -120,7 +120,7 @@ class ActivityPub::Parser::StatusParser
   end
 
   def language
-    lang = raw_language_code || (misskey_software? ? 'ja' : nil)
+    lang = raw_language_code || (no_language_flag_software? ? 'ja' : nil)
     lang.presence && NORMALIZED_LOCALE_NAMES.fetch(lang.downcase.to_sym, lang)
   end
 
@@ -162,15 +162,12 @@ class ActivityPub::Parser::StatusParser
     @object['nameMap'].is_a?(Hash) && !@object['nameMap'].empty?
   end
 
-  def instance_info
-    @instance_info ||= InstanceInfo.find_by(domain: @account.domain)
+  def no_language_flag_software?
+    InstanceInfo.no_language_flag_software?(@account.domain)
   end
 
-  def misskey_software?
-    info = instance_info
-    return false if info.nil?
-
-    %w(misskey calckey).include?(info.software)
+  def invalid_subscription_software?
+    InstanceInfo.invalid_subscription_software?(@account.domain)
   end
 
   def misskey_searchability
diff --git a/app/lib/status_reach_finder.rb b/app/lib/status_reach_finder.rb
index 1058bd30e7..47f8256d21 100644
--- a/app/lib/status_reach_finder.rb
+++ b/app/lib/status_reach_finder.rb
@@ -220,7 +220,7 @@ class StatusReachFinder
   def banned_domains_for_misskey_of_status(status)
     return [] if status.public_searchability?
 
-    from_info = InstanceInfo.where(software: %w(misskey calckey cherrypick sharkey)).pluck(:domain)
+    from_info = InstanceInfo.where(software: InstanceInfo::INVALID_SUBSCRIPTION_SOFTWARES).pluck(:domain)
     from_domain_block = DomainBlock.where(detect_invalid_subscription: true).pluck(:domain)
     (from_info + from_domain_block).uniq
   end
diff --git a/app/models/instance_info.rb b/app/models/instance_info.rb
index da6396517a..45278e37f9 100644
--- a/app/models/instance_info.rb
+++ b/app/models/instance_info.rb
@@ -37,19 +37,43 @@ class InstanceInfo < ApplicationRecord
 
   CIRCLE_AVAILABLE_SOFTWARES = %w(fedibird).freeze
 
+  MISSKEY_FORKS = %w(
+    calckey
+    cherrypick
+    firefish
+    iceshrimp
+    meisskey
+    misskey
+    rosekey
+    sharkey
+    tanukey
+  ).freeze
+
+  INVALID_SUBSCRIPTION_SOFTWARES = MISSKEY_FORKS - %w(firefish)
+
+  PROXY_ACCOUNT_SOFTWARES = MISSKEY_FORKS
+
+  NO_LANGUAGE_FLAG_SOFTWARES = MISSKEY_FORKS - %w(firefish)
+
   class << self
-    def emoji_reaction_available?(domain)
-      return Setting.enable_emoji_reaction if domain.nil?
-
-      Rails.cache.fetch("emoji_reaction_available_domain:#{domain}") { load_emoji_reaction_available(domain) }
-    end
-
     def available_features(domain)
       return local_features if domain.nil?
 
       Rails.cache.fetch("domain_available_features:#{domain}") { load_available_features(domain) }
     end
 
+    def invalid_subscription_software?(domain)
+      INVALID_SUBSCRIPTION_SOFTWARES.include?(software_name(domain))
+    end
+
+    def proxy_account_software?(domain)
+      PROXY_ACCOUNT_SOFTWARES.include?(software_name(domain))
+    end
+
+    def no_language_flag_software?(domain)
+      NO_LANGUAGE_FLAG_SOFTWARES.include?(software_name(domain))
+    end
+
     private
 
     def load_available_features(domain)
@@ -77,7 +101,7 @@ class InstanceInfo < ApplicationRecord
     def feature_available?(info, softwares, feature_name)
       return false if info.nil?
 
-      softwares.include?(software_name(info)) || metadata_features(info)&.include?(feature_name) || false
+      softwares.include?(info.software) || metadata_features(info)&.include?(feature_name) || false
     end
 
     def metadata_features(info)
@@ -86,7 +110,16 @@ class InstanceInfo < ApplicationRecord
       info.data['metadata']['features']
     end
 
-    def software_name(info)
+    def software_name(domain)
+      Rails.cache.fetch("software_name:#{domain}") { load_software_name(domain) }
+    end
+
+    def load_software_name(domain)
+      return 'threads' if domain == 'threads.net'
+
+      info = InstanceInfo.find_by(domain: domain)
+      return nil if info.nil?
+
       info.software
     end
   end
@@ -94,7 +127,7 @@ class InstanceInfo < ApplicationRecord
   private
 
   def reset_cache
-    Rails.cache.delete("emoji_reaction_available_domain:#{domain}")
     Rails.cache.delete("domain_available_features:#{domain}")
+    Rails.cache.delete("software_name:#{domain}")
   end
 end
diff --git a/app/services/activitypub/process_account_service.rb b/app/services/activitypub/process_account_service.rb
index 6897ef3068..474fad59d5 100644
--- a/app/services/activitypub/process_account_service.rb
+++ b/app/services/activitypub/process_account_service.rb
@@ -286,7 +286,7 @@ class ActivityPub::ProcessAccountService < BaseService
       bio = searchability_from_bio
       return bio unless bio.nil?
 
-      return misskey_software? ? misskey_searchability_from_indexable : :direct
+      return invalid_subscription_software? ? misskey_searchability_from_indexable : :direct
     end
 
     if audience_searchable_by.any? { |uri| ActivityPub::TagManager.instance.public_collection?(uri) }
@@ -328,11 +328,8 @@ class ActivityPub::ProcessAccountService < BaseService
     @instance_info ||= InstanceInfo.find_by(domain: @domain)
   end
 
-  def misskey_software?
-    info = instance_info
-    return false if info.nil?
-
-    %w(misskey calckey).include?(info.software)
+  def invalid_subscription_software?
+    InstanceInfo.invalid_subscription_software?(@domain)
   end
 
   def subscribable_by
diff --git a/spec/models/instance_info_spec.rb b/spec/models/instance_info_spec.rb
index 32208ee8f8..2694de65ac 100644
--- a/spec/models/instance_info_spec.rb
+++ b/spec/models/instance_info_spec.rb
@@ -59,4 +59,37 @@ RSpec.describe InstanceInfo do
       expect(subject).to be true
     end
   end
+
+  describe '.software_name' do
+    before do
+      Fabricate(:instance_info, domain: 'misskey.io', software: 'misskey')
+      Fabricate(:instance_info, domain: 'novelskey.tarbin.net', software: 'tanukey')
+      Fabricate(:instance_info, domain: 'mastodon.social', software: 'mastodon')
+      Fabricate(:instance_info, domain: 'firefish.social', software: 'firefish')
+    end
+
+    it 'detect invalid subscription domains' do
+      expect(described_class.invalid_subscription_software?('misskey.io')).to be true
+      expect(described_class.invalid_subscription_software?('novelskey.tarbin.net')).to be true
+      expect(described_class.invalid_subscription_software?('mastodon.social')).to be false
+      expect(described_class.invalid_subscription_software?('firefish.social')).to be false
+      expect(described_class.invalid_subscription_software?('ohagi.social')).to be false
+    end
+
+    it 'detect proxy account software domains' do
+      expect(described_class.proxy_account_software?('misskey.io')).to be true
+      expect(described_class.proxy_account_software?('novelskey.tarbin.net')).to be true
+      expect(described_class.proxy_account_software?('mastodon.social')).to be false
+      expect(described_class.proxy_account_software?('firefish.social')).to be true
+      expect(described_class.proxy_account_software?('ohagi.social')).to be false
+    end
+
+    it 'detect no language software domains' do
+      expect(described_class.no_language_flag_software?('misskey.io')).to be true
+      expect(described_class.no_language_flag_software?('novelskey.tarbin.net')).to be true
+      expect(described_class.no_language_flag_software?('mastodon.social')).to be false
+      expect(described_class.no_language_flag_software?('firefish.social')).to be false
+      expect(described_class.no_language_flag_software?('ohagi.social')).to be false
+    end
+  end
 end