Asakusa-Yu

The water is famously HOT. Nine distinct reviewers describe it as very hot, with temperature estimates of 'about 44°C' (hot tub), 'about 45°C', '47°C hot / 42°C lukewarm', 'nearly 45°C in both', 'about 46°C, both nearly the same', and one who read 45°C on the lukewarm tub's thermometer and guessed 47°C for the hot one. Several could only stay in for 30 seconds to 3 minutes, and even the 'lukewarm' tub was too hot for some without adding cold tap water. However, four reviewers found the temperature fine or milder than reviews had led them to expect (one guessing about 41°C) — so it varies by visit. One reviewer notes the hot water itself feels soft.

This is a classic indoor-only sento: two adjoining tubs, hot (rear) and lukewarm (front). Three reviewers note the divider between the two tubs sits below the waterline so the water mixes, which several say makes both tubs nearly the same temperature. No reviewer mentions any outdoor bath or sauna; one reviewer explicitly frames the place as bathing-only with nowhere to linger, and adding cold water to the front tub is accepted practice per two reviewers.

Bring your own soap and towel: four distinct reviewers state no shampoo or soap is provided in the bathroom (two of them note towels/shampoo can be purchased at the desk), and one reviewer doubts towel rental exists. One reviewer reports the hair dryer is free.

Clothes go in open wicker baskets, not lockers — five distinct reviewers say the old wooden lockers are unusable or unused (one says they barely open and everyone uses baskets). Three of those reviewers note a small modern lockbox exists for valuables only.

Fully gender-separated in the traditional style: one reviewer notes separate men's and women's entrances, and three reviewers describe the dividing wall between the men's and women's baths (which has a tropical-fish aquarium set into it). No mixed bathing or women-only hours mentioned.

Owner-attended: you pay the 450 yen directly to the proprietor at the entrance. Accounts differ on the setup — one reviewer describes a traditional bandai (attendant seat) between the men's and women's sides, another says there is no bandai but the friendly owner greets you in the men's side, and a third paid the owner who was sitting at a PC just inside the changing room.