I went to this restaurant years ago in Tokyo with some of my old NOVA J-staff and students after the company went bankrupt in 2007.
It was some traditional themed restaurant with a Oni dinner show where two guys in masks with smoke bombs dressed as Oni (demons) went table to table and told dirty jokes and generally were “ill behaved” and to get them to go away you had to give them a drink. They’d have their drink (and they’d really drink it) talk to your table a bit making funny lewd comments and then move on to the next table.
It was really kind of cool and that has to be the best job ever for these guys.
JapanLove just blogged an Oni mask which reminded me of this.