GET /topic/%23%E3%81%82%E3%81%AA%E3%81%9F%E3%81%AE%E3%83%84%E3%82%A4%E3%83%BC%E3%83%88%E3%81%8B%E3%82%89%E6%A1%83%E5%A4%AA%E9%83%8E%E3%82%92%E6%9B%B8%E3%81%8F