diff --git a/src/main/java/org/ntlab/hellorest/resources/CommentsYoshikawaRest.java b/src/main/java/org/ntlab/hellorest/resources/CommentsYoshikawaRest.java
new file mode 100644
index 0000000..afa9258
--- /dev/null
+++ b/src/main/java/org/ntlab/hellorest/resources/CommentsYoshikawaRest.java
@@ -0,0 +1,45 @@
+package org.ntlab.hellorest.resources;
+
+import org.springframework.stereotype.Component;
+
+import javax.ws.rs.*;
+import java.util.ArrayList;
+
+@Component
+@Path("/comments-yoshikawa")
+public class CommentsYoshikawaRest {
+    ArrayList<String> comments = new ArrayList<>();         // 文字列の可変長リスト
+
+    @GET
+    public String getComments() {       // すべてのコメントを取得
+        String result = "";
+        for (String comment: comments) {       // 拡張for文
+            result = result + comment + "<br>";
+        }
+        return result;
+    }
+
+    @POST
+    public void addComment(@FormParam("comment-yoshikawa") String comment) {      // 新規コメントを追加
+        comments.add(comment);
+    }
+
+    @DELETE
+    public void clearComments() {       // すべてのコメントを削除
+        comments.clear();
+    }
+
+    @Path("/{cId}")
+    @GET
+    public String getComment(@PathParam("cId") String cId) {    // 指定したコメントを取得
+        int id = Integer.parseInt(cId);
+        return comments.get(id);
+    }
+
+    @Path("/{cId}")
+    @PUT
+    public void addComment(@PathParam("cId") String cId, @FormParam("comment-yoshikawa") String comment) {       // 指定したコメントを上書き
+        int id = Integer.parseInt(cId);
+        comments.set(id, comment);
+    }
+}
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