There are no explicit rules regarding tattoos on the official website, and there are no user reports. Therefore, it is unclear whether tattoos are allowed.
The official website of Kamenoi Hotel Ito mentions that customers with tattoos are not allowed to use the public bath, but notes that if tattoos can be concealed using stickers so they cannot be seen by other guests, then usage is possible. Given this mixed information, it's likely that admission for those with visible tattoos may be denied.
There are no explicit rules regarding tattoos on the official website, and there are no user reports. Therefore, it is unclear whether tattoos are allowed.