The Merciless Trap (1961)

Detective Izaki investigates the murder of a young woman, leading to an ex-convict turned truck driver named Ninomiya. However, Ninomiya swears by an alibi that he was with a call girl named Masako at the time of the murder and does not recognize the dead woman. Without evidence, Ninomiya is released as he and Izaki search for the girl that can prove Ninomiya's innocence. When they find Masako, she claims to have never meet Ninomiya. However, she is threaten by a gang of criminals connected to a fuel scandal. The criminals hire a professional assassin to kill Ninomiya. Masako comes to realize that her silence may lead to the death of an innocent man. She joins up with Ninomiya as the pair finds themselves at the mercy of the thugs.