diff --git a/index-b.html b/index-b.html
index becb483..546032d 100644
--- a/index-b.html
+++ b/index-b.html
@@ -871,7 +871,7 @@
                     今後の新機能も含む
                 </li>
             </ul>
-            <a href="#" class="btn-full btn-accent">
+            <a href="https://buy.stripe.com/test_9B67sEbN3fowfMW4jwenS00" class="btn-full btn-accent" target="_blank" rel="noopener">
                 <i data-lucide="credit-card" style="width:15px;height:15px;"></i>
                 ¥500 で購入する
             </a>
diff --git a/index-c.html b/index-c.html
index dfb94ef..b74016e 100644
--- a/index-c.html
+++ b/index-c.html
@@ -308,8 +308,7 @@
         <span class="amount">500</span>
     </div>
     <p class="hero-price-note">買い切り — 追加請求なし</p>
-    <!-- TODO: 以下の href を Stripe Payment Link URL に差し替える -->
-    <a class="btn-buy" href="#" id="buyBtn">
+    <a class="btn-buy" href="https://buy.stripe.com/test_9B67sEbN3fowfMW4jwenS00" id="buyBtn" target="_blank" rel="noopener">
         <i data-lucide="credit-card" style="width:16px;height:16px;"></i>
         購入する
     </a>
diff --git a/index.html b/index.html
index 330fc34..9f867a5 100644
--- a/index.html
+++ b/index.html
@@ -508,7 +508,7 @@
                 <div class="tier-name">Full Access</div>
                 <div class="tier-price"><sup>¥</sup>500</div>
                 <div class="tier-desc">記録無制限・AI分析・全機能。買い切り。</div>
-                <a href="#" class="btn btn-primary" id="buyBtn">
+                <a href="https://buy.stripe.com/test_9B67sEbN3fowfMW4jwenS00" class="btn btn-primary" id="buyBtn" target="_blank" rel="noopener">
                     <i data-lucide="credit-card" style="width:14px;height:14px;"></i>
                     購入する
                 </a>