diff --git a/app/controllers/related_contents_controller.rb b/app/controllers/related_contents_controller.rb
index 1ea9e02f9..8e2cd854d 100644
--- a/app/controllers/related_contents_controller.rb
+++ b/app/controllers/related_contents_controller.rb
@@ -3,6 +3,8 @@ class RelatedContentsController < ApplicationController
 
   skip_authorization_check
 
+  respond_to :html, :js
+
   def create
     if relationable_object && related_object
       @relationable.relate_content(@related)
@@ -15,6 +17,24 @@ class RelatedContentsController < ApplicationController
     redirect_to @relationable
   end
 
+  def flag
+    @related = RelatedContent.find_by(id: params[:id])
+
+    Flag.flag(current_user, @related)
+    Flag.flag(current_user, @related.opposite_related_content)
+
+    render template: 'relationable/_refresh_flag_actions'
+  end
+
+  def unflag
+    @related = RelatedContent.find_by(id: params[:id])
+
+    Flag.unflag(current_user, @related)
+    Flag.unflag(current_user, @related.opposite_related_content)
+
+    render template: 'relationable/_refresh_flag_actions'
+  end
+
   private
 
   def valid_url?
diff --git a/config/routes.rb b/config/routes.rb
index 429e5a862..40eb2e139 100644
--- a/config/routes.rb
+++ b/config/routes.rb
@@ -462,7 +462,12 @@ Rails.application.routes.draw do
     root to: "dashboard#index"
   end
 
-  resources :related_contents, only: [:create]
+  resources :related_contents, only: [:create] do
+    member do
+      put :flag
+      put :unflag
+    end
+  end
 
   # GraphQL
   get '/graphql', to: 'graphql#query'