Ken (Roger Kwok), has mastered mahjong and is nicknamed "The Half-Century Man" because he once won 50 hands of mahjong in a roll. Everybody expects him to succeed his father, Uncle Man (Ha Yu), to be the Grandmaster of Kungfu Mahjong. However, Uncle Man has a heart attack on his 60th birthday and is hospitalized. Sophie, Uncle Man's new wife takes the opportunity to persuade him to leave his estate to her instead of his son. Uncle Man tells her that she would get her wish if she beats Ken in a game of mahjong.

Meanwhile, Ken falls in love with Nancy (Shirley Yeung), a lady of rotten luck. All her previous boyfriends were either bankrupt or had died in accidents. Ken's fortunes go downhill instantly, to the extent that when he plays mahjong with Sophie and her lover, Bowie, he's almost cleaned out.