Shinzō, the heir of the prominent Edo lumber dealer Yamashiroya, left home when his stubborn father, Chōzaemon, dismissed his lover, the maid Oyasu. Shinzō and Oyasu set up a household near a soba shop in Fukagawa, but Shinzō struggled financially, turning to gambling and fighting, while Oyasu worked as a tea server in a theater, constantly harassed by a small-time gangster, Rikichi, for cigarette money. The only ones concerned about Shinzō and Oyasu were Shinzō’s sister, Omitu, and her dance teacher, Oyoshi. Later, Shinzō managed to get a job at another lumber dealer, but after a conflict with the detective Hansuke, who was also infatuated with Oyasu, Shinzō accidentally dropped lumber into the river and was fired. Unaware that Oyasu had borrowed money from a bar to repay the lumber dealer, Shinzō left to earn money in the Mito clan's crew quarters and ended up rescuing Rikichi from a dice game trouble.
