“By the late Tokugawa period, the [Asakusa] Sensoji area had been transformed into a commercial center that boasted permanent as well as occasional markets. In particular, special fairs, held three times annually, amused visitors and shoppers: the ennichi (day for connection) fair held on the tenth day of the seventh month, the Bon fair held on the twelfth and thirteenth days of the seventh month, and a year-end fair called toshi-no-ichi (fair of the year) held on the seventh and eighteenth days of the twelfth month.
“Among these, the ennichi fair created a spectacular scene, with the display and sale of colorful Japanese ground cherries (hozuki) on every corner of the temple precincts. Acccording to a Sensoji chronicle, an Atago deity appeared in a dream to a man living in Shiba and told him that drinking ground-cherry tea on the tenth day of the seventh month would eradicate dysentery in adults and intestinal parasites in children. The ground cherry soon came to represent the ennichi fair itself.
“The Bon fair, held two days after the ennichi fair, was an occasion for Edo families to purchase ritual items to decorate their Bon altars during the Bon festival. The year-end fair was similar to the Bon fair, but its magnitude and popularity far exceeded that of other fairs.”
– Prayer and Play in Late Tokugawa Japan: Asakusa Sensōji and Edo Society, by Nam-Lin Hur, 2000