Proof of the Man 1977

Johnny Hayward [Joe Yamanaka] is a young man from New York who receives a windfall, buys new clothes, and boards a flight to Japan. Soon after he arrives, he is found fatally stabbed in an elevator of a Tokyo hotel, at the same moment as a fashion show by designer Kyōko Yasugi [Mariko Okada] is taking place. The police, including Munesue [Yūsaku Matsuda] and his partner [Hajime Hana], begin the investigation, and the only clue is the dying man’s last words: > “straw hat”.

At the same time, Naomi [Bunjaku Han], who is having an extramarital affair, is accidentally run over by Yasugi’s son. He and his girlfriend dump her body in the sea, but they leave behind his watch, a clue that haunts him. He confesses to his mother, Kyōko Yasugi, who suggests he flee to New York with his girlfriend.

Munesue grows suspicious that Kyōko knows more than she reveals. He travels to New York to uncover more about the dead man, pairing up with American detective Ken Shuftan [George Kennedy], who seems to be the same man who killed Munesue’s father. In New York, Munesue discovers that the young man is the son of a Black American soldier and a Japanese woman. He also encounters Yasugi’s son, who deliberately provokes Shuftan into shooting him dead. Munesue then returns to Japan and intensifies his investigation, growing convinced that Kyōko holds the answers he needs.

Back in Japan, the investigation deepens as Munesue uncovers a painful history: Kyōko was a prostitute in the postwar years, and Johnny Hayward was her mixed-race son. Confronting Kyōko with the truth, Munesue reveals that Johnny’s death was a calculated act to protect her reputation, and Kyōko commits suicide to escape the consequences. In a parallel thread, Shuftan continues his search in America for Johnny’s father, only to learn that the man is already dead, and his pursuit ends disastrously when Shuftan is stabbed and dies.