I go to this place PURELY for the karaoke rooms. I love being able to rent a room with my friends and sing without being self-conscious or surrounded by random people.
As far as the food, their sushi menu is not that great (I mean, come on, they don't even have volcano rolls). I've never had anything else, either, but I don't really see a point in going here for the restaurant.
Basically, I'd go for karaoke and nothing more.