The Robot Restaurant is a cabaret where actors, singers, and dancers perform a live show with mechanical robots in Shinjuku Tokyo. Entrance is a steep 6000円, and it's recommended to make reservations on the website before arriving.
Overall, it's an expensive relic left over from the 90s bubble. The show itself was kind of fun, but leans too hard in to the "weird Japan" stereotype. Even as a one time thing, I think it can be skipped.