This collection of six linked stories probes the inner lives of the simple, unsophisticated tradespeople and big-hearted courtesans of the Fukagawa district, a place crisscrossed with canals fed by the Sumida River in the shitamachi ("low city") section of old Edo. With its title taken from the name of one such canal, Sendaibori (Sendai Canal) tells of the mismatched loves of the four main characters from the perspective of Kyusuke, 21, a salesman for the foodstuffs wholesaler, Uosen. Kyusuke has a thing for the owner's daughter, Oyo, who remains unmarried at 25 due to health issues. For her part, ever since childhood, Oyo has had eyes only for Yohei, 25, the handsome and capable heir to the high-class restaurant Kinogawa, one of Uosen's prime customers. Yohei, however, is scheduled to wed the daughter of the noodle-shop owner. Then Yohei's little sister, the 17-year-old Oritsu, asks Kyusuke to marry her, and Yohei urges him to accept. Kyusuke has long looked to Yohei as a big-brother figure, but earnest to a fault and still a virgin, he remains indecisive, worrying in particular about what will happen to Oyo. He thinks it would be best for her if she could marry Yohei, but it seems clear that that's not going to happen. As Yohei's nuptials approach, Oyo, who generally never goes anywhere, seeks to go out with him. It begins as a double date with Kyusuke and Oritsu, but later they split into two couples, and Oyo gives up her virginity to Yohei. Afterwards, she takes to her bed, then on the day before Yohei's wedding, she drowns herself in the Sendai Canal. Shaken by her death and furious at Yohei, Kyusuke spurns the talk of marriage with Oritsu and resolves to remain single.