They have it on amazon -
https://www.amazon.co.jp/s/ref=search_black_curtain_yes?_encoding=UTF8&field-keywords=%E3%81%AD%E3%81%A4%E3%81%A8%E3%82%8Abathtime&ie=UTF8&redirect=true&rh=i%3Aaps%2Ck%3A%E3%81%AD%E3%81%A4%E3%81%A8%E3%82%8Abathtime&url=search-alias%3Daps