Big Shots Die at Dawn (1961)

Upon returning home, a young man discovers that his father, who has just been elected mayor, has been murdered. Determined to uncover the truth behind his father's death, he embarks on a quest to track down the killer. Along the way, he finds himself entangled in the conflicts between two rival yakuza gangs, navigating a dangerous world of crime and vengeance as he seeks justice for his father.