Rubbers Seven

At the convenience store, "Rubbers 7", the owner, small-time yakuza leader Tounomoto Munenori, has a mad devotion to the sport of table tennis -- so much so that he'll challenge shoplifters to a match. They win, they go free. They lose, they have to work for him at lousy rates. Needless to say, he's a very good player. But one girl, Soeno Natsuki, changes the rules on him...--summary from animenewsnetwork.com