These large round metal plates rotate cars so they can be loaded into the elevators in the correct orientation. Throughout Japan the cost of land and demand so high that these multi-story parking buildings can be constructed. They are self automated but I typically see some staff manning the controls at places like this, however at this location I did not see any staff. This building also had a nice traditional Japanese style room for you to wait as your car gets carried down from above. The waiting room is visible behind the green question mark.