GET /topic/%23%E3%83%95%E3%82%A1%E3%82%A4%E3%83%B3%E3%83%80%E3%83%BC%E8%B6%8A%E3%81%97%E3%81%AE%E7%A7%81%E3%81%AE%E4%B8%96%E7%95%8C