diff --git a/backend/scripts/dev.sh b/backend/scripts/dev.sh
index 3f7dd2d..931f214 100755
--- a/backend/scripts/dev.sh
+++ b/backend/scripts/dev.sh
@@ -21,8 +21,8 @@ else
 fi
 
 # ルートの.envファイルを読み込んでサーバーを起動
-# Node.jsのメモリ制限を1GBに設定
-export NODE_OPTIONS="--max-old-space-size=1024"
+# Node.jsのメモリ制限を1GBに設定、WASMモジュールを有効化（Prisma 7対応）
+export NODE_OPTIONS="--max-old-space-size=1024 --experimental-wasm-modules"
 
 if command -v pnpm >/dev/null 2>&1; then
 	pnpm tsx --env-file=../.env src/server.ts
diff --git a/backend/src/lib/prisma.ts b/backend/src/lib/prisma.ts
index 6c033b9..7179116 100644
--- a/backend/src/lib/prisma.ts
+++ b/backend/src/lib/prisma.ts
@@ -1,4 +1,4 @@
-import { PrismaClient } from "../generated/prisma/edge";
+import { PrismaClient } from "../generated/prisma";
 import { withAccelerate } from "@prisma/extension-accelerate";
 
 // PrismaClientのシングルトンインスタンスを作成
diff --git a/backend/src/routes/modules/speech.routes.ts b/backend/src/routes/modules/speech.routes.ts
index 5d9585c..5fe1771 100644
--- a/backend/src/routes/modules/speech.routes.ts
+++ b/backend/src/routes/modules/speech.routes.ts
@@ -397,8 +397,8 @@ speech.openapi(ttsRoute, async (c) => {
 
 		const { text, voiceId, modelId } = c.req.valid("json");
 
-		// Use default voiceId if not provided (Rachel - a natural sounding voice)
-		const selectedVoiceId = voiceId || "lhTvHflPVOqgSWyuWQry";
+		// Use default voiceId from environment or fallback
+		const selectedVoiceId = voiceId || process.env.ELEVENLABS_VOICE_ID || "lhTvHflPVOqgSWyuWQry";
 
 		const audioStream = await textToSpeech(
 			apiKey,
diff --git a/frontend/src/app/layout.tsx b/frontend/src/app/layout.tsx
index ca5cc4e..f480d60 100644
--- a/frontend/src/app/layout.tsx
+++ b/frontend/src/app/layout.tsx
@@ -37,7 +37,7 @@ export default function RootLayout({
         <link rel="apple-touch-icon" href="/renai_icon.png" />
         <link
           rel="preload"
-          href="/models/hachisannomaki.vrm"
+          href="/models/maki.vrm"
           as="fetch"
           crossOrigin="anonymous"
         />
diff --git a/frontend/src/app/simulation/page.tsx b/frontend/src/app/simulation/page.tsx
index a8984bd..52e3a33 100644
--- a/frontend/src/app/simulation/page.tsx
+++ b/frontend/src/app/simulation/page.tsx
@@ -82,7 +82,7 @@ export default function SimulationPage() {
   const avatarModelUrl = useMemo(() => {
     if (selectedAvatar === "male") return "/models/rento.vrm";
     if (selectedAvatar === "neutral") return "/models/kouta.vrm";
-    return "/models/hachisannomaki.vrm"; // female
+    return "/models/maki.vrm"; // female
   }, [selectedAvatar]);
 
   // 背景の保存/復元s