Arriving in Tokyo, Yoichi meets older Michio, who gets him a job in the yakuza-owned nightclub where he works. A country boy with guts but no grasp of big-city rules, Yoichi immediately makes an enemy of club manager Matsuo, at the same time impressing mob boss Otani with his courage. Intervening when he sees Matsuo mistreating his lover, Yuko, Yoichi gets a knife wound and a discarded gangster’s moll for his troubles. Recruited by Otani to collect gambling debts, Yoichi and Michio witness the absence of passion between the boss and his girl, Miya. Moving in on Michio, Miya confides in him that Otani is a junkie, driven to drugs by his increasing lack of nerve.
