diff --git a/main.c b/main.c
index e74e427..57ec82d 100644
--- a/main.c
+++ b/main.c
@@ -1,8 +1,10 @@
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+
 #include <weechat/weechat-plugin.h>
 #include <curl/curl.h>
 #include <cjson/cJSON.h>
-#include <stdlib.h>
-#include <string.h>
 
 WEECHAT_PLUGIN_NAME("chatwork");
 WEECHAT_PLUGIN_DESCRIPTION("Chatwork対応");
@@ -21,24 +23,231 @@ typedef struct {
 
 typedef struct {
   CURLcode result;
-  char *data;
+  cJSON *data;
 } ApiResponse;
 
-ApiResponse makeApiRequest (const ApiRequest *request) {
-  // TODO
-}
+typedef struct {
+  char *data;
+  size_t size;
+} Buffer;
 
 size_t WriteCallback (void* contents, size_t size, size_t nmemb, void* userp) {
   size_t totalSize = size * nmemb;
-  char** buffer_ptr = (char**)userp;
-  char* temp = realloc(*buffer_ptr, strlen(*buffer_ptr) + totalSize + 1);
+  Buffer *buffer = (Buffer *)userp;
+  char *temp = realloc(buffer->data, buffer->size + totalSize + 1);
   if (temp == NULL) return 0;
-  *buffer_ptr = temp;
-  memcpy(*buffer_ptr + strlen(*buffer_ptr), contents, totalSize);
-  (*buffer_ptr)[strlen(*buffer_ptr) + totalSize] = '\0';
+  buffer->data = temp;
+  memcpy(buffer->data + buffer->size, contents, totalSize);
+  buffer->size += totalSize;
+  buffer->data[buffer->size] = '\0';
   return totalSize;
 }
 
+ApiResponse makeApiRequest (const ApiRequest *request) {
+  ApiResponse response = {0};
+
+  CURL *curl = curl_easy_init();
+  if (!curl) {
+    return response;
+  }
+
+  Buffer readBuffer = { NULL, 0 };
+  struct curl_slist *headers = NULL;
+  char header[256];
+  snprintf(header, sizeof(header), "X-ChatWorkToken: %s", request->token);
+  headers = curl_slist_append(headers, header);
+
+  curl_easy_setopt(curl, CURLOPT_URL, request->url);
+  curl_easy_setopt(curl, CURLOPT_HTTPHEADER, headers);
+
+  curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, WriteCallback);
+  curl_easy_setopt(curl, CURLOPT_WRITEDATA, &readBuffer);
+
+  response.result = curl_easy_perform(curl);
+  response.data = cJSON_Parse(readBuffer.data);
+  free(readBuffer.data);
+
+  curl_slist_free_all(headers);
+  curl_easy_cleanup(curl);
+
+  return response;
+}
+
+void getMeInfo (struct t_gui_buffer *buffer, const char *token) { 
+  ApiRequest request = {
+    .url = "https://api.chatwork.com/v2/me",
+    .token = token,
+  };
+  ApiResponse response = makeApiRequest(&request);
+
+  if (response.result != CURLE_OK) {
+    weechat_printf(buffer, "GETリクエストエラー：%s\n", curl_easy_strerror(response.result));
+  } else {
+    cJSON *root = response.data;
+    if (root != NULL) {
+      const char *name = cJSON_GetObjectItem(root, "name")->valuestring;
+      weechat_printf(buffer, "GETリクエストに成功：%s\n", name);
+    } else {
+      weechat_printf(buffer, "JSONパーシングエラー。\n");
+    }
+
+    cJSON_Delete(root);
+  }
+}
+
+void getRoomsInfo (struct t_gui_buffer *buffer, const char *token) { 
+  ApiRequest request = {
+    .url = "https://api.chatwork.com/v2/rooms",
+    .token = token,
+  };
+  ApiResponse response = makeApiRequest(&request);
+
+  if (response.result != CURLE_OK) {
+    weechat_printf(buffer, "GETリクエストエラー：%s\n", curl_easy_strerror(response.result));
+  } else {
+    cJSON *root = response.data;
+    if (root != NULL) {
+      int size = cJSON_GetArraySize(root);
+
+      for (int i = 0; i < size; i++) {
+        cJSON *room = cJSON_GetArrayItem(root, i);
+        int room_id = cJSON_GetObjectItem(room, "room_id")->valueint;
+        const char *name = cJSON_GetObjectItem(room, "name")->valuestring;
+        const char *type = cJSON_GetObjectItem(room, "type")->valuestring;
+        if (strcmp(type, "my") == 0) {
+          weechat_printf(buffer, "%d - %s\n", room_id, name);
+        } else if (strcmp(type, "direct") == 0) {
+          weechat_printf(buffer, "%d - DM %s\n", room_id, name);
+        } else if (strcmp(type, "group") == 0) {
+          weechat_printf(buffer, "%d - グループ %s\n", room_id, name);
+        }
+      }
+    } else {
+      weechat_printf(buffer, "JSONパーシングエラー。\n");
+    }
+
+    cJSON_Delete(root);
+  }
+}
+
+void populateUserList (struct t_gui_buffer *buffer, const char *token, int room_id) {
+  char url[256];
+  snprintf(url, sizeof(url), "https://api.chatwork.com/v2/rooms/%d/members", room_id);
+
+  ApiRequest req = {
+    .url = url,
+    .token = token,
+  };
+  ApiResponse res = makeApiRequest(&req);
+
+  if (res.result != CURLE_OK) {
+    weechat_printf(buffer, "GETリクエストエラー：%s\n", curl_easy_strerror(res.result));
+    return;
+  }
+
+  cJSON *members = res.data;
+  if (members != NULL) {
+    weechat_nicklist_remove_all(buffer);
+
+    for (int i = 0; i < cJSON_GetArraySize(members); i++) {
+      cJSON *member = cJSON_GetArrayItem(members, i);
+      const char *name = cJSON_GetObjectItem(member, "name")->valuestring;
+      const char *role = cJSON_GetObjectItem(member, "role")->valuestring;
+      char *rolepref = NULL;
+      char *rolecol = NULL;
+      if (strcmp(role, "admin") == 0) {
+        rolepref = "@";
+        rolecol = "weechat.color.*214";
+      }
+      weechat_nicklist_add_nick(buffer, NULL, name, "weechat.color.nicklist_nick", rolepref, rolecol, 1);
+    }
+    cJSON_Delete(members);
+  } else {
+    weechat_printf(buffer, "JSONパーシングエラー。\n");
+  }
+}
+
+void getRoom (struct t_gui_buffer *buffer, const char *token, int room_id) {
+  char url1[256];
+  char url2[256];
+  snprintf(url1, sizeof(url1), "https://api.chatwork.com/v2/rooms/%d", room_id);
+  snprintf(url2, sizeof(url2), "https://api.chatwork.com/v2/rooms/%d/messages?force=1", room_id);
+
+  ApiRequest req = {
+    .url = url1,
+    .token = token,
+  };
+  ApiResponse res = makeApiRequest(&req);
+
+  if (res.result != CURLE_OK) {
+    weechat_printf(buffer, "GETリクエストエラー：%s\n", curl_easy_strerror(res.result));
+  } else {
+    cJSON *bufroot = res.data;
+    if (bufroot != NULL) {
+      const char *bufname = cJSON_GetObjectItem(bufroot, "name")->valuestring;
+      struct t_gui_buffer *buf = weechat_buffer_new(bufname, NULL, NULL, NULL, NULL, NULL, NULL);
+      cJSON_Delete(bufroot);
+
+      populateUserList(buf, token, room_id);
+      weechat_buffer_set(buf, "display", "1");
+      weechat_buffer_set(buf, "nicklist", "1");
+
+      ApiRequest request = {
+        .url = url2,
+        .token = token,
+      };
+      ApiResponse response = makeApiRequest(&request);
+
+      if (response.result != CURLE_OK) {
+        weechat_printf(buffer, "GETリクエストエラー：%s\n", curl_easy_strerror(response.result));
+      } else {
+        cJSON *root = response.data;
+        if (root != NULL) {
+          for (int i = 0; i < cJSON_GetArraySize(root); i++) {
+            cJSON *message = cJSON_GetArrayItem(root, i);
+            cJSON *account = cJSON_GetObjectItem(message, "account");
+            const char *name = cJSON_GetObjectItem(account, "name")->valuestring;
+            const char *body = cJSON_GetObjectItem(message, "body")->valuestring;
+            int send_time = cJSON_GetObjectItem(message, "send_time")->valueint;
+
+            // send_timeはUnixから日時に
+            char timestamp[64];
+            time_t raw_time = send_time;
+            struct tm *timeinfo = localtime(&raw_time);
+            strftime(timestamp, sizeof(timestamp), "%Y-%m-%d %H:%M:%S", timeinfo);
+
+            char fbody[4096];
+
+            // TODO: 返事
+            //if (sscanf(body, "[To:%d]", &account_id) == 1) {
+            //  weechat_printf(buffer, "%sさんに返事：\n", user);
+            //} else {
+
+            // ファイル共有
+            if (strstr(body, "[download:") != NULL) {
+              char download_id[64];
+              sscanf(body, "[info][title][dtext:file_uploaded][/title][download:%63[^]]]", download_id);
+              snprintf(fbody, sizeof(fbody), "%s | [ファイル] https://www.chatwork.com/gateway/download_file.php?bin=1&file_id=%s&preview=0", name, download_id);
+            } else {
+              snprintf(fbody, sizeof(fbody), "%s | %s", name, body);
+            }
+
+            // TODO: nickはメッセージの前に表示する
+            weechat_printf_date_tags(buf, raw_time, NULL, "%s\n", fbody);
+            //} // TODO: 返事
+          }
+        } else {
+          weechat_printf(buffer, "JSONパーシングエラー。\n");
+        }
+
+        cJSON_Delete(root);
+      }
+    } else {
+      weechat_printf(buffer, "JSONパーシングエラー。\n");
+    }
+  }
+}
+
 int chatwork_command_cb (const void *pointer, void *data, struct t_gui_buffer *buffer, int argc, char **argv, char **argv_eol) {
   weechat_printf(buffer, "Chatworkコマンドを実行しました。\n");
   const char *token = weechat_config_string(chatwork_config_token);
@@ -47,43 +256,35 @@ int chatwork_command_cb (const void *pointer, void *data, struct t_gui_buffer *b
     return WEECHAT_RC_ERROR;
   }
 
-  CURL *curl = curl_easy_init();
-  if (!curl) {
-    weechat_printf(buffer, "libcurlを起動出来なかった。\n");
-    return WEECHAT_RC_ERROR;
+  if (argc < 2 || (argc == 2 && strcmp(argv[1], "help") == 0)) {
+    weechat_printf(buffer, "使い方： /chatwork me - ユーザー情報を表示\n");
+    weechat_printf(buffer, "         /chatwork rooms - 部屋を表示\n");
+    weechat_printf(buffer, "         /chatwork join 部屋番号 - 部屋に参加\n");
+    weechat_printf(buffer, "         /chatwork upload パス - ファイルをアップロードする\n");
+    return WEECHAT_RC_OK;
   }
 
-  char *readBuffer = calloc(1, 1);
-  curl_easy_setopt(curl, CURLOPT_URL, "https://api.chatwork.com/v2/me");
-
-  struct curl_slist *headers = NULL;
-  char header[256];
-  snprintf(header, sizeof(header), "X-ChatWorkToken: %s", token);
-  headers = curl_slist_append(headers, header);
-  curl_easy_setopt(curl, CURLOPT_HTTPHEADER, headers);
-
-  curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, WriteCallback);
-  curl_easy_setopt(curl, CURLOPT_WRITEDATA, &readBuffer);
-
-  CURLcode res = curl_easy_perform(curl);
-  if (res != CURLE_OK) {
-    weechat_printf(buffer, "GETリクエストエラー：%s\n", curl_easy_strerror(res));
-  } else {
-    cJSON *root = cJSON_Parse(readBuffer);
-    if (root != NULL) {
-      const char *name = cJSON_GetObjectItem(root, "name")->valuestring;
-      weechat_printf(buffer, "GETリクエストに成功：%s\n", name);
-      cJSON_Delete(root);
+  if (strcmp(argv[1], "me") == 0) {
+    getMeInfo(buffer, token);
+  } else if (strcmp(argv[1], "rooms") == 0) {
+    getRoomsInfo(buffer, token);
+  } else if (strcmp(argv[1], "join") == 0) {
+    if (argc == 3) {
+      getRoom(buffer, token, atoi(argv[2]));
     } else {
-      weechat_printf(buffer, "JSONパーシングエラー。\n");
+      weechat_printf(buffer, "部屋番号をご入力下さい。\n");
     }
+  } else if (strcmp(argv[1], "upload") == 0) {
+    if (argc == 3) {
+      getRoom(buffer, token, atoi(argv[2]));
+    } else {
+      weechat_printf(buffer, "パスをご入力下さい。\n");
+    }
+  } else {
+    weechat_printf(buffer, "不明なコマンド：%s\n", argv[1]);
+    weechat_printf(buffer, "すべてのコマンドを表示するには、/chatwork helpを実行して下さい。\n");
   }
 
-  // 掃除
-  curl_slist_free_all(headers);
-  curl_easy_cleanup(curl);
-  free(readBuffer);
-
   return WEECHAT_RC_OK;
 }