diff --git a/CHANGES.md b/CHANGES.md
index 764d6cf1..15478f82 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -42,6 +42,8 @@
   - @melpon
 - [ADD] WebSocket の Close を取得できるよう SendOnWsClose を SoraSignalingObserver に追加する
   - @tnoho
+- [ADD] DataChannel のみの接続で type: close がやってきた場合に正しく切断されるようにする
+  - @melpon
 - [FIX] HTTP Proxy 利用時の Websocket 初期化で insecure_ メンバ変数が初期化されていなかったのを修正
   - @melpon
 - [FIX] SoraSignalingConfig の client_cert と client_key に渡す必要がある値を、ファイルパスからファイルの内容に修正
diff --git a/include/sora/data_channel.h b/include/sora/data_channel.h
index 5446f7b2..ab711de2 100644
--- a/include/sora/data_channel.h
+++ b/include/sora/data_channel.h
@@ -44,6 +44,7 @@ class DataChannel : public std::enable_shared_from_this<DataChannel> {
   void Close(const webrtc::DataBuffer& disconnect_message,
              std::function<void(boost::system::error_code)> on_close,
              double disconnect_wait_timeout);
+  void SetOnClose(std::function<void(boost::system::error_code)> on_close);
 
   void AddDataChannel(
       rtc::scoped_refptr<webrtc::DataChannelInterface> data_channel);
diff --git a/src/data_channel.cpp b/src/data_channel.cpp
index 56270dc5..9b5b1951 100644
--- a/src/data_channel.cpp
+++ b/src/data_channel.cpp
@@ -69,6 +69,10 @@ void DataChannel::Close(const webrtc::DataBuffer& disconnect_message,
   auto data_channel = it->second;
   data_channel->Send(disconnect_message);
 }
+void DataChannel::SetOnClose(
+    std::function<void(boost::system::error_code)> on_close) {
+  on_close_ = on_close;
+}
 
 void DataChannel::AddDataChannel(
     rtc::scoped_refptr<webrtc::DataChannelInterface> data_channel) {
diff --git a/src/sora_signaling.cpp b/src/sora_signaling.cpp
index 7d09e90c..34eb6774 100644
--- a/src/sora_signaling.cpp
+++ b/src/sora_signaling.cpp
@@ -1644,6 +1644,23 @@ void SoraSignaling::OnMessage(
           },
           CreateIceError(
               "Failed to SetOffer in re-offer message via DataChannel"));
+    } else if (type == "close") {
+      // グレースフルシャットダウンする
+      int code = json.at("code").to_number<int>();
+      std::string reason = json.at("reason").as_string().c_str();
+      // on_close を設定しておいて、あとは DataChannel が閉じるのを待つだけ
+      dc_->SetOnClose([self = shared_from_this(), code,
+                       reason](boost::system::error_code ec) {
+        if (code == 1000) {
+          self->SendOnDisconnect(SoraSignalingErrorCode::CLOSE_SUCCEEDED,
+                                 "Succeeded to close DataChannel: reason=" + reason);
+        } else {
+          self->SendOnDisconnect(
+              SoraSignalingErrorCode::CLOSE_SUCCEEDED,
+              "Failed to close DataChannel: code=" + std::to_string(code) +
+                  " ec=" + ec.message());
+        }
+      });
     }
     return;
   }
diff --git a/test/.testparam.example.json b/test/.testparam.example.json
index f24a9f96..1351b057 100644
--- a/test/.testparam.example.json
+++ b/test/.testparam.example.json
@@ -23,10 +23,34 @@
       "capture_width": 1024,
       "capture_height": 768,
       "video_bit_rate": 0,
-      "video_codec_type": "H264",
+      "video_codec_type": null,
       "simulcast": false,
       "use_hardware_encoder": true,
       "openh264": null,
+      "ignore_disconnect_websocket": null,
+      "client_id": null,
+
+      // "data_channels": [
+      //   {
+      //     // required
+      //     "label": "#test",
+      //     "direction": "sendrecv",
+      //     // optional
+      //     "ordered": null,
+      //     "max_packet_life_time": null,
+      //     "max_retransmits": null,
+      //     "protocol": null,
+      //     "compress": null,
+      //   }
+      // ],
+      "data_channels": null,
+
+      // 0 - verbose
+      // 1 - info
+      // 2 - warning
+      // 3 - error
+      // 4 - none
+      "log_level": 2,
     },
 
     "signaling_urls": ["必須"],
diff --git a/test/hello.cpp b/test/hello.cpp
index 360d3124..c1aff2cd 100644
--- a/test/hello.cpp
+++ b/test/hello.cpp
@@ -71,6 +71,15 @@ void HelloSora::Run() {
   config.video_bit_rate = config_.video_bit_rate;
   config.multistream = true;
   config.simulcast = config_.simulcast;
+  if (config_.ignore_disconnect_websocket) {
+    config.ignore_disconnect_websocket = *config_.ignore_disconnect_websocket;
+  }
+  if (!config_.client_id.empty()) {
+    config.client_id = config_.client_id;
+  }
+  if (!config_.data_channels.empty()) {
+    config.data_channels = config_.data_channels;
+  }
   conn_ = sora::SoraSignaling::Create(config);
 
   boost::asio::executor_work_guard<boost::asio::io_context::executor_type>
@@ -142,43 +151,80 @@ int main(int argc, char* argv[]) {
     config.signaling_urls.push_back(x.as_string().c_str());
   }
   config.channel_id = v.as_object().at("channel_id").as_string().c_str();
-  if (auto it = v.as_object().find("role"); it != v.as_object().end()) {
-    config.role = it->value().as_string();
+  boost::json::value x;
+  auto get = [](const boost::json::value& v, const char* key,
+                boost::json::value& x) -> bool {
+    if (auto it = v.as_object().find(key);
+        it != v.as_object().end() && !it->value().is_null()) {
+      x = it->value();
+      return true;
+    }
+    return false;
+  };
+  if (get(v, "role", x)) {
+    config.role = x.as_string();
+  }
+  if (get(v, "video", x)) {
+    config.video = x.as_bool();
+  }
+  if (get(v, "audio", x)) {
+    config.audio = x.as_bool();
+  }
+  if (get(v, "capture_width", x)) {
+    config.capture_width = x.to_number<int>();
+  }
+  if (get(v, "capture_height", x)) {
+    config.capture_height = x.to_number<int>();
   }
-  if (auto it = v.as_object().find("video"); it != v.as_object().end()) {
-    config.video = it->value().as_bool();
+  if (get(v, "video_bit_rate", x)) {
+    config.video_bit_rate = x.to_number<int>();
   }
-  if (auto it = v.as_object().find("audio"); it != v.as_object().end()) {
-    config.audio = it->value().as_bool();
+  if (get(v, "video_codec_type", x)) {
+    config.video_codec_type = x.as_string();
   }
-  if (auto it = v.as_object().find("capture_width");
-      it != v.as_object().end()) {
-    config.capture_width = boost::json::value_to<int>(it->value());
+  if (get(v, "simulcast", x)) {
+    config.simulcast = x.as_bool();
   }
-  if (auto it = v.as_object().find("capture_height");
-      it != v.as_object().end()) {
-    config.capture_height = boost::json::value_to<int>(it->value());
+  if (get(v, "client_id", x)) {
+    config.client_id = x.as_string();
   }
-  if (auto it = v.as_object().find("video_bit_rate");
-      it != v.as_object().end()) {
-    config.video_bit_rate = boost::json::value_to<int>(it->value());
+  if (get(v, "ignore_disconnect_websocket", x)) {
+    config.ignore_disconnect_websocket = x.as_bool();
   }
-  if (auto it = v.as_object().find("video_codec_type");
-      it != v.as_object().end()) {
-    config.video_codec_type = it->value().as_string();
+  if (get(v, "data_channels", x)) {
+    for (auto&& dc : x.as_array()) {
+      sora::SoraSignalingConfig::DataChannel data_channel;
+      data_channel.label = dc.as_object().at("label").as_string();
+      data_channel.direction = dc.as_object().at("direction").as_string();
+      if (get(dc, "ordered", x)) {
+        data_channel.ordered = x.as_bool();
+      }
+      if (get(dc, "max_packet_life_time", x)) {
+        data_channel.max_packet_life_time = x.to_number<int32_t>();
+      }
+      if (get(dc, "max_retransmits", x)) {
+        data_channel.max_retransmits = x.to_number<int32_t>();
+      }
+      if (get(dc, "protocol", x)) {
+        data_channel.protocol = x.as_string().c_str();
+      }
+      if (get(dc, "compress", x)) {
+        data_channel.compress = x.as_bool();
+      }
+      config.data_channels.push_back(data_channel);
+    }
   }
-  if (auto it = v.as_object().find("simulcast"); it != v.as_object().end()) {
-    config.simulcast = it->value().as_bool();
+  if (get(v, "log_level", x)) {
+    rtc::LogMessage::LogToDebug((rtc::LoggingSeverity)x.to_number<int>());
   }
 
   sora::SoraClientContextConfig context_config;
   context_config.get_android_application_context = GetAndroidApplicationContext;
-  if (auto it = v.as_object().find("use_hardware_encoder");
-      it != v.as_object().end()) {
-    context_config.use_hardware_encoder = it->value().as_bool();
+  if (get(v, "use_hardware_encoder", x)) {
+    context_config.use_hardware_encoder = x.as_bool();
   }
-  if (auto it = v.as_object().find("openh264"); it != v.as_object().end()) {
-    context_config.openh264 = it->value().as_string();
+  if (get(v, "openh264", x)) {
+    context_config.openh264 = x.as_string();
   }
   auto context = sora::SoraClientContext::Create(context_config);
 
diff --git a/test/hello.h b/test/hello.h
index 67b99432..27341f44 100644
--- a/test/hello.h
+++ b/test/hello.h
@@ -14,6 +14,9 @@ struct HelloSoraConfig {
   int video_bit_rate = 0;
   std::string video_codec_type = "H264";
   bool simulcast = false;
+  std::optional<bool> ignore_disconnect_websocket;
+  std::string client_id;
+  std::vector<sora::SoraSignalingConfig::DataChannel> data_channels;
 };
 
 class HelloSora : public std::enable_shared_from_this<HelloSora>,