The number of hot spring bathhouses is rising rapidly in Tokyo and Osaka, allowing more people to enjoy the relaxing baths that were once limited to the countryside.

Healing is the name of the game for the spas tapping the hot mineral water, but Tokyo and Osaka offer distinctly different approaches to therapeutic bathing in the city.

Children are off limits in Tokyo "onsen" because their target clientele is women looking for relaxation or aesthetic treatment. The main selling point for spas in Osaka, however, is that they welcome families.