Kaisuiyu offers guests a choice of a Roman-style marbled bath, a round Jacuzzi bath and a rock-lined rotenburo (open-air bath). The men's baths are larger and somewhat nicer than the women's. In the Meiji Era, shocked foreigners forced the segregation of bathing facilities. Most sento merely added a small separate bath for women. Kaisuiyu wins kudos for alternating the male and female baths. If you forget your soap, shampoo and towels, a set is available for a fee, with both large and small towels.