The flush toilet is one of those Western imports that Japanese industry has adapted to its own special needs and then improved. Though you'll still find a lot of traditional Japanese toilets at older public facilities and in the countryside, the Washlet toilet, with that surprising little spray nozzle, has become so ubiquitous as to be a standard fixture in Japanese life.
Washlet is a registered brand name for Toto, which dominates the toilet bowl business in Japan, and though most histories of the Washlet start in the 1980s, spray function toilets (onsui senjo benza) have been around in one form or another since the 1960s, and number 2 Inax's Shower Toilet seems to be actually older than the Washlet. With traditional Japanese toilets there is no contact between the person and the porcelain, and when Western toilet bowls first made their appearance here, Japanese were perplexed by the seat for various reasons. Some were concerned about hygiene, while others simply found them too cold. The first improvement the Japanese made was to heat the seat.