This is one of the most bizarre video games i've ever seen, and so of course it must be Japanese.
The object of the game appears simple, you have to jam a big plastic finger up someone's rear end. Why? I have no idea.
Built into the cabinet is a bent over backside, and on the screen in front of you appears the expression of the person as you shove the finger inside. The harder you shove the finger inside, the more points you score.