As anyone who clicked on this question is probably aware, shots and shooters have a tendency to make people lose control. Many cocktail bars in Tokyo pride themselves on their relaxed atmospheres, enabling customers to have a few lazy drinks before calling it a night. That's clearly not the environment where bartenders would want people becoming loud and annoying because they put back too much tequila. Certainly there are plenty of places with completely different atmospheres, where they are happy to serve you as many shots as you like. If you must have shots, drink them there instead!