Proof of the Man (1977), directed by Junya Satō, is a gripping Japanese-American crime drama that delves into themes of racial identity, post-war trauma, and the lingering effects of Japan's occupation. The narrative unfolds as a young Black American, Johnny Hayward, is found fatally stabbed in a Tokyo hotel elevator, uttering the cryptic words "straw hat" before dying. Detective Koichiro Munesue (Yūsaku Matsuda) leads the investigation, which uncovers a complex web of secrets tied to prominent fashion designer Kyōko Yasugi (Mariko Okada) and her son, Kyohei (Kōichi Iwaki). The case takes Munesue to New York City, where he collaborates with NYPD detective Ken Shuftan (George Kennedy), confronting both the mystery and his own personal history.