Bathing
From IkataWiki
Customs relating to bathing in Japan are quite different from those in the US.
Bathing is a popular method of relaxation in Japan. Japanese people usually bathe in the evening, and for longer periods of time than Americans. The bath is initially drawn extremely hot; each member of the family then bathes in this same water. For this reason, they clean their bodies by showering before entering the bath so that the water may stay relatively clean.
Bathroom
In Japan, the bathroom houses only the shower (usually outside the tub) and the bathtub. The toilet and sink are located in separate rooms.
Japanese bathrooms (not to be confused with the toilet room) almost always have drains in the floors because showering is performed outside the tub. In a homestay situation where an American host family hosts a Japanese visitor, in many cases the family must explain to the visitor that the bathroom floor does not have a drain. If not, the family may find its bathroom floor sopping wet.
Toilet
Toilets in Japanese homes are housed in a room separate from the bath and shower. For this reason, Japanese visitors may ask for the "toilet" rather than the "bathroom"; this is not an attempt to be crude.
Toilets in Japan come in many varieties. "Japanese style" toilets are essentially pits in the floor that the user squats over. Many Americans find these to be awkward to use.
Most homes these days have "Western style" toilets, which are basically the same as American toilets, except that they often have a faucet at the top where water comes out when you flush. This is to wash your hands with, as the sink is often housed in a separate room from the toilet.
Some fancier Western style toilets have heated seats and built-in water jet washing/bidet functions. Don't be shy when trying them out.

