Japan has tons of small bars and restaurants that are run by one person. This is simply not possible in many other countries, already restricted by law. Most of this kind of places however, do take a good amount of courage to enter. Often the entrances are almost hidden, you cannot see inside or the place is full of crazy looking people.
But entering them results often in excellent experiences where you can communicate with drunk locals, make friends, get attention and otherwise just enjoy the crazyish atmosphere.