Youth of the Beast

is a 1963 Japanese yakuza film directed by Seijun Suzuki. Much of the film is set in Tokyo, Japan. Synopsis Joji Mizuno (Joe Shishido), a former Kobe Metropolitan Police Department detective fired after being convicted of embezzlement, is released from prison. During his incarceration, his partner, Detective Takeshita, died in an apparent lovers' suicide with a call girl. However, Mizuno believes that the adultery and the suicide were staged by Nomoto Enterprises, a yakuza group whose prostitution operations Takeshita was investigating. Posing as a gangster, Mizuno infiltrates the Nomoto organization in order to find out the truth. At Takeshita's memorial service, Mizuno promises his dead partner's wife, Kumiko (Misako Watanabe), that he will find her husband's killers. Mizuno is partnered with a young soldier named Goro Minami (Eimei Esumi) and quickly earns the respect of both Minami and the eccentric head of the Nomoto group, Tetsuo Nomoto (Akiji Kobayashi), by re-securing protection payments from a business that had switched allegiances to the Sanko Family, Nomoto's sworn rivals. Sanko's second-in-command Shigeru Takechi (Eiji Gō), tries to kidnap Mizuno in retaliation, but Mizuno manages to turn the tables and takes Takechi hostage instead, forcing him to take him to his boss. Mizuno meets with Sanko Family head Shinzuke Onodera (Kinzo Shin) and surprises him by offering to spy on Nomoto for money. Mizuno is approached by Keiko (Naomi Hoshi), one of Nomoto's mistresses who recognizes him as a cop from her days as a prostitute. She blackmails him into helping her identify and kill Nomoto's mysterious "sixth mistress", the one who secretly runs the prostitution racket, so she can take her place. Aside from Nomoto himself, the only one who knows the sixth mistress's identity is Nomoto's gay brother Hideo (Tamio Kawachi), who is infamous for going berserk and attacking anyone who impugns the reputation of their prostitute mother. Mizuno goes to the love hotel Hideo uses as his base of operations and tries to gather information by posing as a client, only to get into a fight with him after realizing that Hideo was involved in framing Takeshita. Ishizaki (Shiro Yanase), one of Nomoto's enforcers, breaks up the fight, and Mizuno is brought before Nomoto and interrogated about his reasons for prying into the prostitution ring.