Time Out says
Up on the 9th floor of the Rakutenchi entertainment complex in Kinshicho, this 24-hour, men-only spa seems aimed mainly at office workers who've missed their last train home. The facilities include an onsen hot-spring bath and a pair of saunas, while the in-house restaurant opens at 6am and keeps serving food until the wee hours of the morning (5am on Friday and Saturday). If you're looking to get some sleep, there are three relaxation rooms equipped with reclining chairs, the quietest of which comes with an optional wake-up call from the staff.
9F Rakutenchi Bldg, 4-27-14 Kotobashi, Sumida-ku
|Transport:||Kinshicho Station (Sobu, Hanzomon lines)|
|Price:||Entrance ¥2,400; 60 mins only ¥1,250, late-night surcharge (midnight-5am) ¥1,100|
|Opening hours:||24 hours daily (Sun until 11pm, Mon from 10am)|