diff --git a/README.rst b/README.rst
index d4c99aa..f396f95 100644
--- a/README.rst
+++ b/README.rst
@@ -29,7 +29,7 @@ Example
 
 .. code:: python
 
-   from voicevox import Client
+   from vvclient import Client
    import asyncio
 
 
diff --git a/examples/basic.py b/examples/basic.py
index 6e9c14d..1ae65a0 100644
--- a/examples/basic.py
+++ b/examples/basic.py
@@ -1,4 +1,4 @@
-from voicevox import Client
+from vvclient import Client
 import asyncio
 
 
diff --git a/examples/get_speakers.py b/examples/get_speakers.py
index 410b3f8..953df73 100644
--- a/examples/get_speakers.py
+++ b/examples/get_speakers.py
@@ -1,4 +1,4 @@
-from voicevox import Client
+from vvclient import Client
 import asyncio
 
 
diff --git a/examples/multi_synthesis.py b/examples/multi_synthesis.py
index f7eb385..31d0643 100644
--- a/examples/multi_synthesis.py
+++ b/examples/multi_synthesis.py
@@ -1,4 +1,4 @@
-from voicevox import Client
+from vvclient import Client
 import asyncio
 
 
diff --git a/tests/test_basic.py b/tests/test_basic.py
index 7aa2573..1c8a262 100644
--- a/tests/test_basic.py
+++ b/tests/test_basic.py
@@ -1,10 +1,10 @@
 import pytest
 
-from voicevox import Client
+from vvclient import Client
 
 
 @pytest.mark.asyncio
 async def test_basic():
     async with Client() as client:
-        audio_query = await client.create_audio_query("こんにちは！", style_id=1)
-        await audio_query.synthesis(style_id=1)
+        audio_query = await client.create_audio_query("こんにちは！", speaker=1)
+        await audio_query.synthesis(speaker=1)
diff --git a/tests/test_fetch_version.py b/tests/test_fetch_version.py
index f144fa6..5f815ca 100644
--- a/tests/test_fetch_version.py
+++ b/tests/test_fetch_version.py
@@ -1,6 +1,6 @@
 import pytest
 
-from voicevox import Client
+from vvclient import Client
 
 
 @pytest.mark.asyncio
diff --git a/tests/test_init.py b/tests/test_init.py
index 43ab4a5..e32e5d7 100644
--- a/tests/test_init.py
+++ b/tests/test_init.py
@@ -1,6 +1,6 @@
 import pytest
 
-from voicevox import Client
+from vvclient import Client
 
 
 @pytest.mark.asyncio
diff --git a/vvclient/audio_query.py b/vvclient/audio_query.py
index 6f1a718..2ac8107 100644
--- a/vvclient/audio_query.py
+++ b/vvclient/audio_query.py
@@ -20,8 +20,8 @@ async def synthesis(
     ) -> bytes:
         params = {
             "speaker": speaker,
-            "enable_interrogative_upspeak": enable_interrogative_upspeak,
+            "enable_interrogative_upspeak": "true" if enable_interrogative_upspeak else "false",
         }
         if core_version:
             params["core_version"] = core_version
-        return await self._http.create_audio_query(params, self.data)
+        return await self._http.synthesis(params, self.data)
diff --git a/vvclient/client.py b/vvclient/client.py
index 0e362f8..e3967a6 100644
--- a/vvclient/client.py
+++ b/vvclient/client.py
@@ -3,6 +3,7 @@
 from typing import Optional
 
 from .http import HTTPClient
+from .audio_query import AudioQuery
 
 
 class Client:
@@ -12,15 +13,39 @@ class Client:
     ----------
     base_uri : str
         Base URI of the VOICEVOX Engine"""
-    def __init__(self, base_uri: str) -> None:
+    def __init__(self, base_uri: str = "http://localhost:50021") -> None:
         self.http = HTTPClient(base_uri)
 
+    async def __aenter__(self) -> "Client":
+        return self
+
+    async def __aexit__(self, *args):
+        await self.close()
+
     async def close(self) -> None:
         await self.http.close()
 
     async def create_audio_query(
         self, text: str, speaker: int, *, core_version: Optional[str] = None
-    ):
+    ) -> AudioQuery:
+        """
+        Create audio query
+
+        Parameters
+        ----------
+        text: str
+            Voice text
+        speaker: int
+            speaker type
+        core_version: Optional[str]
+            voicevox_core version
+
+        Returns
+        -------
+        audio_query: AudioQuery
+            Audio query
+        """
         params = {"text": text, "speaker": speaker}
         if core_version:
             params["core_version"] = core_version
+        return AudioQuery(self.http, await self.http.create_audio_query(params))
diff --git a/vvclient/http.py b/vvclient/http.py
index 5f9d0c2..5fd882d 100644
--- a/vvclient/http.py
+++ b/vvclient/http.py
@@ -31,7 +31,7 @@ async def request(self, route: Route, **kwargs) -> Any:
                 return await response.json()
             else:
                 return await response.read()
-        elif res.status == 404:
+        elif response.status == 404:
             raise NotFoundError("Not found")
         else:
             raise HTTPException(await response.text(), response.status)
@@ -42,7 +42,7 @@ async def close(self) -> None:
     async def create_audio_query(
         self, params: Dict[str, Union[str, int]]
     ) -> AudioQueryType:
-        return await self.request(Route("POST", "/audio_query"), json=params)
+        return await self.request(Route("POST", "/audio_query"), params=params)
 
     async def synthesis(
         self, params: Dict[str, Union[str, int]], audio_query: AudioQueryType