This is very much a family establishment so you may not get peace and quiet, but there are about as many different types of baths as you could hope for from a day onsen. A good place for first-timers.
Myojin no Yu is a popular day onsen in Adachi Ward, northeast Tokyo. It is in the middle of a residential district near the Naka River, and many of those who use the onsen live in the area. This creates a sort of family-orientated, local atmosphere, and it does get quite busy in the evenings. While it may be easier to relax at other onsen, Myojin no Yu does have a lot of different baths both inside and outside, as well as a large (TV-fitted) sauna. The male and female bathing areas are identical, each with stone baths, wooden baths, and small pot tubs, among others. But it’s the outside that is probably the main draw. A small garden of bathtubs of different depths and temperatures. Especially in the colder months, one can easily pass an hour or so lost in thoughts while lying supine in the shallow baths and gazing up at the sky. There is also a restaurant attached (more canteen-style with the usual menu of ramen and ton-katsu for ¥800 or so), as well as massage services.