diff --git a/app/controllers/tasks_controller.rb b/app/controllers/tasks_controller.rb
index c4d0b576..4f0ba6aa 100644
--- a/app/controllers/tasks_controller.rb
+++ b/app/controllers/tasks_controller.rb
@@ -19,6 +19,7 @@ def new
     @projects = Project.all
     @tags = Tag.all
     @task_states = TaskState.all
+    @task.description = params[:desc_header]
 
     project_id = params[:project_id]
     unless project_id.nil?
@@ -41,6 +42,10 @@ def create
 
     if @task.save!
       flash[:success] = "タスクを追加しました"
+      matched = task_params[:description].match(/\[AI([0-9]+)\]/)
+      if matched != nil
+        ActionItem.find(matched[1]).update(task_url: tasks_path + "/" + @task.id.to_s)
+      end
       redirect_to tasks_path
     else
       redirect_back fallback_location: new_task_path
diff --git a/app/models/action_item.rb b/app/models/action_item.rb
new file mode 100644
index 00000000..7d295f50
--- /dev/null
+++ b/app/models/action_item.rb
@@ -0,0 +1,13 @@
+class ActionItem < ApplicationRecord
+  after_create :set_uid
+
+  def uid
+    "%04d" % self.id
+  end
+
+  private
+
+  def set_uid
+    self.update(uid: uid)
+  end
+end
diff --git a/app/models/document.rb b/app/models/document.rb
index 933a3b01..af04fde8 100644
--- a/app/models/document.rb
+++ b/app/models/document.rb
@@ -8,4 +8,18 @@ class Document < ApplicationRecord
   validates :end_at, presence: true
   validates :location, presence: true
   #validates :project, presence: true
+  before_validation :add_unique_action_item_marker
+
+  def add_unique_action_item_marker
+    desc = ""
+    self.description.each_line {|line|
+      matched = line.match(/-->\((.+)\)/)
+      if matched != nil
+        @action_item = ActionItem.create(task_url: nil)
+        line.gsub!(/-->\(.+\)/, "-->(#{matched[1]} !#{@action_item.uid})")
+      end
+      desc += line
+    }
+    self.description = desc
+  end
 end
diff --git a/app/views/documents/show.html.erb b/app/views/documents/show.html.erb
index 8e225f14..861f3d19 100644
--- a/app/views/documents/show.html.erb
+++ b/app/views/documents/show.html.erb
@@ -10,8 +10,24 @@
   <p class="text-xl">所属プロジェクト:
     <%= link_to_if  @document.project&.name, @document.project&.name, @document.project %>
   <p class="text-xl block font-bold mb-2">文書内容</p>
-    <div class="jay_document">
-      <%== JayFlavoredMarkdownConverter.new(@document.description).content %>
+  <div class="jay_document">
+    <% desc = JayFlavoredMarkdownConverter.new(@document.description).content %>
+    <% desc.each_line do |line| %>
+      <% matched = line.match(/\([^ ]+ !([0-9]+)\)/) %>
+      <% if matched != nil %>
+        <%== $` %>
+        <% task_url = ActionItem.find_by(uid:matched[1].to_i).task_url %>
+        <% if task_url != nil %>
+          <%= link_to matched[0], task_url.to_s %>
+        <% else %>
+          <% message = "Created from [AI#{matched[1]}](#{request.url})" %>
+          <%= link_to matched[0], new_task_path(desc_header: message) %>
+        <% end %>
+        <%== $' %>
+      <% else %>
+        <%== line %>
+      <% end %>
+    <% end %>
     </div>
   </p>
 </div>
diff --git a/app/views/tasks/show.html.erb b/app/views/tasks/show.html.erb
index 418f936f..0ba2b9da 100644
--- a/app/views/tasks/show.html.erb
+++ b/app/views/tasks/show.html.erb
@@ -20,7 +20,16 @@
 
 <div class="my-3">
   <p class="text-xl block font-bold mb-2">説明</p>
-  <%= @task.description %>
+    <% @task.description.each_line do |line| %>
+      <% matched = line.match(/\((.+)\)/) %>
+      <% if matched != nil %>
+        <%== $` %>
+        <%= link_to matched[0], matched[1] %>
+        <%== $' %>
+      <% else %>
+        <%== line %>
+      <% end %>
+    <% end %>
 </div>
 
 <div class="my-3">
diff --git a/db/migrate/20221006041706_create_action_items.rb b/db/migrate/20221006041706_create_action_items.rb
new file mode 100644
index 00000000..a6ee000e
--- /dev/null
+++ b/db/migrate/20221006041706_create_action_items.rb
@@ -0,0 +1,10 @@
+class CreateActionItems < ActiveRecord::Migration[6.1]
+  def change
+    create_table :action_items do |t|
+      t.integer :uid
+      t.string :task_url
+
+      t.timestamps
+    end
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index d95b7e13..08afda81 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -10,7 +10,14 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 2021_11_07_082503) do
+ActiveRecord::Schema.define(version: 2022_10_06_041706) do
+
+  create_table "action_items", force: :cascade do |t|
+    t.integer "uid"
+    t.string "task_url"
+    t.datetime "created_at", precision: 6, null: false
+    t.datetime "updated_at", precision: 6, null: false
+  end
 
   create_table "api_tokens", force: :cascade do |t|
     t.string "secret"
@@ -58,15 +65,6 @@
     t.datetime "updated_at", precision: 6, null: false
   end
 
-  create_table "task_tag_relations", force: :cascade do |t|
-    t.integer "task_id", null: false
-    t.integer "tag_id", null: false
-    t.datetime "created_at", precision: 6, null: false
-    t.datetime "updated_at", precision: 6, null: false
-    t.index ["tag_id"], name: "index_task_tag_relations_on_tag_id"
-    t.index ["task_id"], name: "index_task_tag_relations_on_task_id"
-  end
-
   create_table "task_tags", force: :cascade do |t|
     t.integer "task_id"
     t.integer "tag_id"
@@ -86,22 +84,12 @@
     t.datetime "created_at", precision: 6, null: false
     t.datetime "updated_at", precision: 6, null: false
     t.integer "tag_id"
-    t.index ["project_id"], name: "index_tasks_on_project_id"
-    t.index ["tag_id"], name: "index_tasks_on_tag_id"
     t.integer "task_state_id"
     t.index ["project_id"], name: "index_tasks_on_project_id"
+    t.index ["tag_id"], name: "index_tasks_on_tag_id"
     t.index ["task_state_id"], name: "index_tasks_on_task_state_id"
   end
 
-  create_table "tasks_tags", force: :cascade do |t|
-    t.integer "task_id", null: false
-    t.integer "tag_id", null: false
-    t.datetime "created_at", precision: 6, null: false
-    t.datetime "updated_at", precision: 6, null: false
-    t.index ["tag_id"], name: "index_tasks_tags_on_tag_id"
-    t.index ["task_id"], name: "index_tasks_tags_on_task_id"
-  end
-
   create_table "users", force: :cascade do |t|
     t.string "name"
     t.string "screen_name"
@@ -121,14 +109,10 @@
   add_foreign_key "documents", "users", column: "creator_id", on_delete: :cascade
   add_foreign_key "projects", "users"
   add_foreign_key "projects", "users", on_delete: :cascade
-  add_foreign_key "task_tag_relations", "tags"
-  add_foreign_key "task_tag_relations", "tasks"
   add_foreign_key "tasks", "projects"
   add_foreign_key "tasks", "projects", on_delete: :cascade
   add_foreign_key "tasks", "tags"
   add_foreign_key "tasks", "task_states"
   add_foreign_key "tasks", "users", column: "assigner_id", on_delete: :cascade
   add_foreign_key "tasks", "users", column: "creator_id", on_delete: :cascade
-  add_foreign_key "tasks_tags", "tags"
-  add_foreign_key "tasks_tags", "tasks"
 end
diff --git a/test/fixtures/action_items.yml b/test/fixtures/action_items.yml
new file mode 100644
index 00000000..ab150e95
--- /dev/null
+++ b/test/fixtures/action_items.yml
@@ -0,0 +1,7 @@
+# Read about fixtures at https://api.rubyonrails.org/classes/ActiveRecord/FixtureSet.html
+
+one:
+  task_url: /1
+
+two:
+  task_url: /1
diff --git a/test/models/action_item_test.rb b/test/models/action_item_test.rb
new file mode 100644
index 00000000..f0b108e7
--- /dev/null
+++ b/test/models/action_item_test.rb
@@ -0,0 +1,7 @@
+require "test_helper"
+
+class ActionItemTest < ActiveSupport::TestCase
+  # test "the truth" do
+  #   assert true
+  # end
+end