Mahjong Hishouden: Naki no Ryuu
Weeping Dragon
麻雀飛翔伝 哭きの竜
The protagonist, Ryuu or Crying Dragon, is a mysterious man who often plays games with the gang members. He only wins by "ron," a move in which one needs to wait for the opponent's tile to complete the win.
*"Ron" is also called "naki" in mahjong, which has the same pronunciation as "crying" in Japanese.