Lam Wai Tung has cancer. In order to raise money for his younger brother Wai Leung to study medicine overseas, he robs some diamond for smuggler Chiu Ying Kau. After the robbery, he hides the real diamonds himself and gives fake diamonds to Chiu, which he then finds out and kills Tung. In order to recover the diamonds, Chiu sets a scheme and makes Leung a murder suspect and arranges his Japanese female subordinate Miko to save him and hide him and nurse his gunshot wounds. Under Miko's attentive treatment, Leung heals and they establish a profound friendship.

Leung's good friend Sergeant Ben Kwok was sent to investigate the case and later he and Leung stumbled across the diamonds that Tung hid. Miko snatches the diamonds and Chiu comes and forces Leung to hand him the diamonds. When he refuses, Chiu wants to kill them. When Miko leaves, she sees Chiu's henchmen on the road, she returns to help Leung and fights with Chiu, where Leung was wounded by Chiu and Leung was killed by Chiu.