I often get asked.
Japanese bathing culture is unique. Japan being a volcanically active country, has thousands of onsens (hot springs) scattered all over Japan. These onsens are known for their therapeutic properties especially for relieving pain. And the Japanese, popular as a hard working class, are addicted to them.
Onsens can be located outdoors (just as in the pic.1) and it was a traditional practice for both the genders to bathe together. It is very rare to find such hot springs now and even if they do, they usually have a separate section for men and women.
Onsens also make for popular tourist destinations. It? not unusual for Japanese can take weekends off only to enjoy onsens. And when deprived of such liberty of time, they go to sento in their neighborhood (public communal bath) which are man-made. (Pic. 2)Gutentor Simple Text.
Most Japanese do have bath tubs at home too, called ofuro along with the showers. But beware, be it an onsen, sento or oufro at home, there are rules to be followed.
While in most countries it would be normal to dip in a foamy tub to clean oneself, but in Japan, you must enter the tub only after thoroughly cleaning yourself so that the water can be used by others who want to use the facility. Great way to optimize the use of water, but again what else do you expect in Japan?