Maki, a porter at the Sakura Hotel, finds a body in Room No. 2 and picks up a piece of paper on which is written "one-third of the key", also the part of a key. From a newspaper he learns that the dead man is an official who has been detained as a suspect in a bribery case involving 150,000,000 yen and that another suspect named Matsunaga is still in custody. Maki realizes that if he can obtain the other two-thirds of the key, he will be a multi-millionaire.
as Maki
as Akiko
as Takako
as Matsunaga
as Hachirô
as Kabu
as Nishi
as Onoda
as Takeuchi
as Miyaoka
as Suzuki
as Yoshimitsu
as Michie Yokota
as Michie's mother Toyo
as Otaguro
as Nabe
as Killer
as Student