GET /topic/%23%E4%BD%95%E7%9C%8C%E6%B0%91%E3%81%8B%E3%83%90%E3%83%AC%E3%82%8B%E3%83%84%E3%82%A4%E3%83%BC%E3%83%88%E3%81%97%E3%82%8D