Baseball player Takatsuka is murdered mid-game in front of a large crowd. The autopsy reveals that he has been killed by a needle coated with a poison used by the Ainu tribe for hunting. The next morning, sports photographer Kawase is killed in the same manner. Kawase’s sister, Yuko, hires Taro Banai, the detective with seven faces, to uncover the truth.

On her wedding day, Makiko is stabbed by a woman in wedding dress. The wound isn't serious but the attacker blows herself up and can't be identified. The attacker is thought to be an ex-girlfriend of Tsutomu, the groom. He gives two names to the police but these two are still alive. But there is still one woman in Tsutomu's mind...