diff --git a/app/controllers/mentor/practices_controller.rb b/app/controllers/mentor/practices_controller.rb
index 504b4014f94..a1d548eae6f 100644
--- a/app/controllers/mentor/practices_controller.rb
+++ b/app/controllers/mentor/practices_controller.rb
@@ -12,9 +12,12 @@ def index
 
   def new
     @practice = Practice.new(pjord_review: true, pjord_auto_check: false)
+    @practice.build_template
   end
 
-  def edit; end
+  def edit
+    @practice.build_template unless @practice.template
+  end
 
   def create
     @practice = Practice.new(practice_params)
@@ -63,7 +66,8 @@ def practice_params
       :summary,
       :ogp_image,
       category_ids: [],
-      practices_books_attributes: %i[id book_id must_read _destroy]
+      practices_books_attributes: %i[id book_id must_read _destroy],
+      template_attributes: %i[id description _destroy]
     )
   end
 
diff --git a/app/models/practice.rb b/app/models/practice.rb
index 412d5ed5ac7..5c56075afc0 100644
--- a/app/models/practice.rb
+++ b/app/models/practice.rb
@@ -25,6 +25,13 @@ class Practice < ApplicationRecord # rubocop:todo Metrics/ClassLength
            source: :user
   has_many :skipped_practices, dependent: :destroy
   has_many :products, dependent: :destroy
+
+  has_one :template, as: :templatable, dependent: :destroy
+  accepts_nested_attributes_for :template, update_only: true, allow_destroy: true,
+                                           reject_if: proc { |attributes|
+                                             attributes['_destroy'] != '1' && attributes['description'].blank?
+                                           }
+
   has_many :questions, dependent: :nullify
   has_many :pages,
            -> { order(updated_at: :desc, id: :desc) },
diff --git a/app/models/template.rb b/app/models/template.rb
new file mode 100644
index 00000000000..c9d19efd539
--- /dev/null
+++ b/app/models/template.rb
@@ -0,0 +1,7 @@
+# frozen_string_literal: true
+
+class Template < ApplicationRecord
+  belongs_to :templatable, polymorphic: true
+
+  validates :description, presence: true
+end
diff --git a/app/views/mentor/practices/_form.html.slim b/app/views/mentor/practices/_form.html.slim
index 9e2869249c6..ccf4aebd039 100644
--- a/app/views/mentor/practices/_form.html.slim
+++ b/app/views/mentor/practices/_form.html.slim
@@ -109,6 +109,26 @@
           = f.check_box :include_progress, class: 'a-toggle-checkbox'
           = f.label :include_progress
             | 進捗の計算に含むようにする場合はチェック
+
+  .form-item
+    label.a-form-label
+      | 提出物のテンプレート
+    = f.fields_for :template do |template_form|
+      - if template_form.object.persisted?
+        .checkboxes
+          ul.checkboxes__items
+            li.checkboxes__item
+              = template_form.check_box :_destroy, class: 'a-toggle-checkbox'
+              = template_form.label :_destroy do
+                | 提出物のテンプレートを削除する
+      .row.js-markdown-parent
+        .col-md-6.col-xs-12
+          = template_form.text_area :description,
+            class: 'a-text-input js-warning-form markdown-form__text-area js-markdown',
+            data: { 'preview': '.js-product-template-preview' }
+        .col-md-6.col-xs-12
+          .js-product-template-preview.a-long-text.is-md.markdown-form__preview
+
   .form-item
     .row.js-markdown-parent
       .col-md-6.col-xs-12
diff --git a/app/views/products/_form.html.slim b/app/views/products/_form.html.slim
index 821fbcd2132..6fd023fba13 100644
--- a/app/views/products/_form.html.slim
+++ b/app/views/products/_form.html.slim
@@ -9,8 +9,10 @@
             | 提出物
           .form-textarea
             .form-textarea__body
+              - template = @product.practice.template&.description
               = f.text_area :body, class: 'a-text-input js-warning-form js-markdown markdown-form__text-area',
-              data: { 'preview': '.js-preview', 'input': '.file-input' }
+              data: { 'preview': '.js-preview', 'input': '.file-input' },
+              value: @product.body.presence || template
             .form-textarea__footer
               .form-textarea__insert
                 label.a-file-insert.a-button.is-xs.is-text-reversal.is-block
diff --git a/db/migrate/20260520061059_create_templates.rb b/db/migrate/20260520061059_create_templates.rb
new file mode 100644
index 00000000000..5f08c8ab8bb
--- /dev/null
+++ b/db/migrate/20260520061059_create_templates.rb
@@ -0,0 +1,10 @@
+class CreateTemplates < ActiveRecord::Migration[8.1]
+  def change
+    create_table :templates do |t|
+      t.references :templatable, polymorphic: true, null: false, index: { unique: true }
+      t.text :description, null: false
+
+      t.timestamps
+    end
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index 99e52cbd229..2ad96e6add0 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -1025,6 +1025,15 @@
     t.index ["user_id"], name: "index_talks_on_user_id"
   end
 
+  create_table "templates", force: :cascade do |t|
+    t.datetime "created_at", null: false
+    t.text "description", null: false
+    t.bigint "templatable_id", null: false
+    t.string "templatable_type", null: false
+    t.datetime "updated_at", null: false
+    t.index ["templatable_type", "templatable_id"], name: "index_templates_on_templatable", unique: true
+  end
+
   create_table "users", id: :serial, force: :cascade do |t|
     t.datetime "accessed_at", precision: nil
     t.boolean "admin", default: false, null: false
diff --git a/test/fixtures/templates.yml b/test/fixtures/templates.yml
new file mode 100644
index 00000000000..fbb7cdfdeba
--- /dev/null
+++ b/test/fixtures/templates.yml
@@ -0,0 +1,3 @@
+one:
+  templatable: practice1 (Practice)
+  description: 提出物のテンプレート
diff --git a/test/models/practice_test.rb b/test/models/practice_test.rb
index a1a63c97d47..183060fbf94 100644
--- a/test/models/practice_test.rb
+++ b/test/models/practice_test.rb
@@ -148,4 +148,36 @@ class PracticeTest < ActiveSupport::TestCase
     assert_equal initial_count + 1, practice.reports_count(include_source: false)
     assert_equal initial_count_including_source + 1, practice.reports_count(include_source: true)
   end
+
+  test 'does not create product template when description is blank' do
+    practice = practices(:practice1)
+    practice.template&.destroy!
+
+    assert_no_difference 'Template.count' do
+      practice.update!(
+        template_attributes: {
+          description: ''
+        }
+      )
+    end
+
+    assert_nil practice.reload.template
+  end
+
+  test 'destroys product template with nested attributes' do
+    practice = practices(:practice1)
+    practice.template&.destroy!
+    template = practice.create_template!(description: '提出物のテンプレート')
+
+    assert_difference 'Template.count', -1 do
+      practice.update!(
+        template_attributes: {
+          id: template.id,
+          _destroy: '1'
+        }
+      )
+    end
+
+    assert_nil practice.reload.template
+  end
 end
diff --git a/test/system/practice/products_test.rb b/test/system/practice/products_test.rb
index e620b0806ae..3599df705b1 100644
--- a/test/system/practice/products_test.rb
+++ b/test/system/practice/products_test.rb
@@ -7,4 +7,10 @@ class Practice::ProductsTest < ApplicationSystemTestCase
     visit_with_auth "/practices/#{practices(:practice1).id}/products", 'komagata'
     assert_equal 'OS X Mountain Lionをクリーンインストールするの提出物 | FBC', title
   end
+
+  test 'shows product template when product template exists' do
+    practice = practices(:practice1)
+    visit_with_auth "/mentor/practices/#{practice.id}/edit", 'komagata'
+    assert_field 'practice_template_attributes_description', with: '提出物のテンプレート'
+  end
 end
diff --git a/test/system/practices/mentor_test.rb b/test/system/practices/mentor_test.rb
index 823668207d5..0deeb064109 100644
--- a/test/system/practices/mentor_test.rb
+++ b/test/system/practices/mentor_test.rb
@@ -21,6 +21,7 @@ class MentorTest < ApplicationSystemTestCase
         end
         fill_in 'practice[goal]', with: 'テストのゴールの内容です'
         fill_in 'practice[memo]', with: 'テストのメンター向けメモの内容です'
+        fill_in 'practice_template_attributes_description', with: 'テストテンプレート'
         uncheck 'practice[pjord_review]', allow_label_click: true
         click_button '登録する'
       end
@@ -28,6 +29,24 @@ class MentorTest < ApplicationSystemTestCase
       assert_not_predicate Practice.order(:created_at).last, :pjord_review?
     end
 
+    test 'can create practice without product template' do
+      visit_with_auth '/mentor/practices/new', 'komagata'
+
+      within 'form[name=practice]' do
+        fill_in 'practice[title]', with: 'テンプレなし'
+        check categories(:category1).name, allow_label_click: true
+        fill_in 'practice[description]', with: 'テストの内容です'
+        fill_in 'practice[goal]', with: 'テストのゴールの内容です'
+        click_button '登録する'
+      end
+
+      assert_text 'プラクティスを作成しました'
+
+      practice = Practice.find_by!(title: 'テンプレなし')
+      visit_with_auth "/mentor/practices/#{practice.id}/edit", 'komagata'
+      assert_empty find_field('practice_template_attributes_description').value
+    end
+
     test 'create practice as a mentor' do
       visit_with_auth '/mentor/practices/new', 'mentormentaro'
       within 'form[name=practice]' do
@@ -39,6 +58,7 @@ class MentorTest < ApplicationSystemTestCase
         end
         fill_in 'practice[goal]', with: 'テストのゴールの内容です'
         fill_in 'practice[memo]', with: 'テストのメンター向けメモの内容です'
+        fill_in 'practice_template_attributes_description', with: 'テストテンプレート'
         click_button '登録する'
       end
       assert_text 'プラクティスを作成しました'
@@ -51,6 +71,7 @@ class MentorTest < ApplicationSystemTestCase
       within 'form[name=practice]' do
         fill_in 'practice[title]', with: 'テストプラクティス'
         fill_in 'practice[memo]', with: 'メンター向けのメモの内容です'
+        fill_in 'practice_template_attributes_description', with: 'テストテンプレート'
         within '#reference_books' do
           click_link '書籍を選択'
         end
@@ -60,6 +81,34 @@ class MentorTest < ApplicationSystemTestCase
       visit "/products/#{product.id}"
       check 'toggle-mentor-memo-body', allow_label_click: true, visible: false
       assert_text 'メンター向けのメモの内容です'
+
+      visit new_product_path(practice_id: practice.id)
+      assert_field 'product[body]', with: 'テストテンプレート'
+    end
+
+    test 'update product template' do
+      practice = practices(:practice1)
+      visit_with_auth "/mentor/practices/#{practice.id}/edit", 'komagata'
+      assert_field 'practice_template_attributes_description', with: '提出物のテンプレート'
+      fill_in 'practice_template_attributes_description', with: '更新後テンプレート'
+      click_button '更新する'
+      assert_text 'プラクティスを更新しました'
+
+      visit new_product_path(practice_id: practice.id)
+      assert_field 'product[body]', with: '更新後テンプレート'
+    end
+
+    test 'deletes product template from practice edit form' do
+      practice = practices(:practice1)
+      visit_with_auth "/mentor/practices/#{practice.id}/edit", 'komagata'
+      check '提出物のテンプレートを削除する', allow_label_click: true
+
+      assert_difference 'Template.count', -1 do
+        click_button '更新する'
+      end
+
+      assert_text 'プラクティスを更新しました'
+      assert_nil practice.reload.template
     end
 
     test 'add a book' do