diff --git a/src/actions/api.ts b/src/actions/api.ts
index c4d6a95..25e2ab3 100644
--- a/src/actions/api.ts
+++ b/src/actions/api.ts
@@ -44,7 +44,7 @@ export abstract class ApiResponseHandler {
     try {
       const response = await this.axiosInstance.post<U>(url, data);
       // console.log("SUCCESS:", response.data);
-      console.log("post", url, response.status);
+      console.log("post", url, response.status, data);
       // console.log("Response Headers: ", response.headers);
       return response.data;
     } catch (error) {
diff --git a/src/actions/asset.ts b/src/actions/asset.ts
index 16b3d39..1d099df 100644
--- a/src/actions/asset.ts
+++ b/src/actions/asset.ts
@@ -102,37 +102,6 @@ export interface AssetModel {
 }
 
 export class Asset extends ApiResponseHandler {
-  private formatDate(date: Date): string {
-    const year = date.getFullYear();
-    const month = date.getMonth() + 1; // getMonth() は0から始まるため、+1する
-    const day = date.getDate();
-
-    return `${year}/${month}/${day}`;
-  }
-
-  public async addAsset(
-    accountString: string,
-    assetSubclassId: AssetSubclass,
-    assetName: string,
-    assetValue: number,
-    assetEntryValue?: number,
-    assetEntryAt?: Date
-  ) {
-    const postData = {
-      "user_asset_det[id]": "",
-      "user_asset_det[sub_account_id_hash]": accountString.split("@")[1],
-      "user_asset_det[asset_subclass_id]": assetSubclassId,
-      "user_asset_det[name]": assetName,
-      "user_asset_det[value]": assetValue,
-      "user_asset_det[entried_price]":
-        assetEntryValue !== undefined ? assetEntryValue : "",
-      "user_asset_det[entried_at]": assetEntryAt
-        ? this.formatDate(assetEntryAt)
-        : "",
-    };
-    return this.post("/bs/portfolio/new", postData);
-  }
-
   public async getAssets(accountString: string): Promise<AssetModel[]> {
     const url = `/accounts/show_manual/${accountString.split("@")[0]}`;
 
@@ -189,6 +158,28 @@ export class Asset extends ApiResponseHandler {
     });
   }
 
+  public async addAsset(
+    accountString: string,
+    assetSubclassId: AssetSubclass,
+    assetName: string,
+    assetValue: number,
+    assetEntryValue?: number,
+    assetEntryAt?: string
+  ) {
+    const postData = {
+      "user_asset_det[id]": "",
+      "user_asset_det[sub_account_id_hash]": accountString.split("@")[1],
+      "user_asset_det[asset_subclass_id]": assetSubclassId,
+      "user_asset_det[name]": assetName,
+      "user_asset_det[value]": assetValue,
+      "user_asset_det[entried_price]":
+        assetEntryValue !== undefined ? assetEntryValue : "",
+      "user_asset_det[entried_at]":
+        assetEntryAt !== undefined ? assetEntryAt : "",
+    };
+    return this.post("/bs/portfolio/new", postData);
+  }
+
   public async deleteAsset(
     accountString: string,
     assetId: string
@@ -209,7 +200,7 @@ export class Asset extends ApiResponseHandler {
     assetName: string,
     assetValue: number,
     assetEntryValue?: number,
-    assetEntryAt?: Date
+    assetEntryAt?: string
   ): Promise<void> {
     const postData = {
       _method: "put",
@@ -220,9 +211,8 @@ export class Asset extends ApiResponseHandler {
       "user_asset_det[value]": assetValue,
       "user_asset_det[entried_price]":
         assetEntryValue !== undefined ? assetEntryValue : "",
-      "user_asset_det[entried_at]": assetEntryAt
-        ? this.formatDate(assetEntryAt)
-        : "",
+      "user_asset_det[entried_at]":
+        assetEntryAt !== undefined ? assetEntryAt : "",
     };
     return this.post("/bs/portfolio/edit", postData);
   }
diff --git a/src/main.ts b/src/main.ts
index 67dcb4a..d57f896 100644
--- a/src/main.ts
+++ b/src/main.ts
@@ -92,14 +92,17 @@ async function main() {
     async (req: Request, res: Response) => {
       try {
         const { accountString } = req.params;
-        const { assetSubclassId, name, value } = req.body;
+        const { assetSubclassId, name, value, entriedPrice, entriedAt } =
+          req.body;
         const _assetSubclassId =
           AssetSubclass[assetSubclassId as keyof typeof AssetSubclass];
         await assetController.addAsset(
           accountString,
           _assetSubclassId,
           name,
-          value
+          value,
+          entriedPrice,
+          entriedAt
         );
         res.status(201).send();
       } catch (error) {
@@ -131,7 +134,8 @@ async function main() {
     async (req: Request, res: Response) => {
       try {
         const { accountString, assetId } = req.params;
-        const { assetSubclassId, name, value } = req.body;
+        const { assetSubclassId, name, value, entriedPrice, entriedAt } =
+          req.body;
         const _assetSubclassId =
           AssetSubclass[assetSubclassId as keyof typeof AssetSubclass];
         await assetController.updateAsset(
@@ -139,7 +143,9 @@ async function main() {
           assetId,
           _assetSubclassId,
           name,
-          value
+          value,
+          entriedPrice,
+          entriedAt
         );
         res.status(204).send();
       } catch (error) {
diff --git a/src/openapi.yaml b/src/openapi.yaml
index dedd20c..4780dfa 100644
--- a/src/openapi.yaml
+++ b/src/openapi.yaml
@@ -124,7 +124,9 @@ paths:
           schema:
             type: string
       requestBody:
-        description: assetSubclassIdは変更することができず、変更前と同じにする必要があります。
+        description: |
+          * `assetSubclassId`は変更できません。必ず同じ値を指定する必要があります。
+          * `entriedPrice`, `entriedAt`は指定がなければ値が初期化されます。
         required: true
         content:
           application/json:
@@ -158,19 +160,18 @@ components:
           description: 資産名
           example: "USD/JPY"
         value:
-          type: number
-          format: float
+          type: integer
           description: 資産価値
           example: 100
         entriedPrice:
-          type: number
-          format: float
+          type: integer
           description: システム登録時の価格
           example: 90
           nullable: true
         entriedAt:
           type: string
           description: システム登録日
+          pattern: '^\d{4}/\d{2}/\d{2}$'
           example: "2022/01/01"
           nullable: true
     AssetSubclass: