Time Out says
Sauna and sleep are the two main features at this new design-driven hotel. While capsule hotels are common in Tokyo, °C has created a new, updated version featuring a clean, modern design inspired by Finnish sauna culture.
The hostel’s steam room is a standout among the city’s many sento (bathhouses). Here, you pour mint-scented water onto hot sauna rocks to create more humidity that will encourage sweating, before cooling down in one of the showers rooms, each of which is set to a different water temperature.