Think of it as a Waterpik for your ass, or a portable bidet. The Japanese have clearly thought out bathroom behavior in a way that makes us look like amateurs. When you're a kid in Japan, you can get a potty training toilet (if you're lucky). If you're a woman and feel shy about bathroom noises, public restrooms are fitted with noisemakers so you don't overflush (to mask "sounds") and waste water. And if toilet paper just isn't doing the job, well, the Toto Portable Travel Washlet will step in.