Watanabe Shogoro's wife, Fuku, has fallen into depression since the death of her mother. Suminoe Hikozaemon introduces him to Yakichi, an oil wholesaler who does trades. It brings some solace to his wife. Yakichi is introduced to Kazusaya Seiemon, a man who tells Yakichi he can become rich if he is backed by him. Though Yakichi initially refuses, Yakichi's mother is killed and he resolves to get revenge. Since money is necessary, he falls under Kazusaya's sway. He teeters between good and evil as Kazusaya works to turn a town into a red light district.