Thermae-Yu

Deruma Onsen is a large public bathhouse near Shinjuku in Tokyo that runs baths, saunas, and rest areas together. It has indoor and outdoor hot baths, a cold bath, jet baths, and dry and salt saunas, and the basement restaurant serves bingsu. Entry uses a key given at the entrance, with payment settled at the end, and the fourth floor has electric reclining beds with power outlets and a heated rock room. A separate late-night charge applies after midnight.