The toilet in Shoko and Keizo's apartment is really neat. Neat in the sense that, rather than built in the reservoir behind the toilet seat, the faucet that refills the tank up with water is positioned outside and on top of the reservoir. It looks like a sink on top of the back of the toilet.
And that's because it is!
In an effort to water, you use the same water that you use to flush the toilet to wash your hand. Definitely neat. At least i thought it was anyway.