Sanbanchi, a mahjong parlor in Ueno, is an old-timer and has a reputation for its delicious homemade weekly menu. Jan Kurogane, grandson of Mikijiro Kurotetsu, visits Sanbanchi to play mahjong with the owner, Kingo Sanbanchi, an acquaintance of Mikijiro. Kingo promises to let Jan spar against him if he achieves one year without losing a match. Meanwhile Otani, the president of the All Mahjong Road Federation, tries to destroy Sanbanchi by sending in various mahjong assassins. There is no end to the number of opponents he faces, regardless, Jan continues to defend his undefeated record by any means necessary.