After a death-defying game of chicken one evening in 1958, Akagi nonchalantly enters a Yakuza Mahjong parlor to shake the cops' trail. Even unfamiliar with the rules of Mahjong, his gambling intuition is enough to save a small time gambler, Nangou, and grant him a seat at the gambling table. As the night progresses, the stakes are raised both within the game and for Akagi, who is under the suspicion of local police. However, Akagi overcomes the situation with his tactics, defiant of both life and chance. When he leaves the gambling house, no one present is in doubt of his genius.

昭和33年、雨が降る夜、場末の雀荘に現れたのが、ずぶ濡れの少年・赤木しげるだった。赤木は南郷の麻雀の姿を見て「死ねば助かるのに……」とつぶやきます。南郷は赤木に何かを感じ取り、命を賭けた勝負にもかかわらず、代打ちを頼むことになった。

牌を握ったことのない素人アカギと、長年闇麻雀で生き残ってきたヤクザ竜崎の勝負は誰の目にも見えていたが……。アカギは初めての麻雀から特別なオーラを放ち、ヤクザ相手の勝負に次々と勝利を収めていく。