User reports lean No.
The official website of SAUNA EAGLE サウナイーグル does not contain explicit regulations regarding tattoos. The terms and conditions mainly cover operating hours and pricing, without mentioning any restrictions on guests with tattoos. There are also no user reports available for reference, making it difficult to determine the policy.
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.