More about Japanese inventions designed to avoid (important and needed) conflict:
Cell Phone Message Warns Train Gropers
The application flashes increasingly threatening messages in bold print on the phone's screen to show to the offender: "Excuse me, did you just grope me?""Groping is a crime," and finally, "Shall we head to the police?"
Pardon me, but is that your hand on my thigh? Squeeze twice for yes, once for no.
Train Gropers or Chikan are actually a HUGE problem in Japan. Of course my solution to this issue was to yell, "Everyone please look at the pervert!" or to figure out who it was and grab them with my long dagger-like finger nails and whisper menacingly, "Touch me again and you won't get that hand back."