ウォシュレット

ウォシュレット = washlet
or
warm-water cleaning toilet seat (温水洗浄便座: onsui senjō benza)

This kind of tiolet, made popular by TOTO (東陶機器株式会社), is now installed in more than half of Japanese households. It has 7 functions (heated seat, multiple cleaning functions, different water spraying speed and flow, music...etc. I don't know them all). But once you've used one, all the others not like it just seem so uncivilized!