The term Suijin (literally water kami or water deity) refers to the many heavenly and earthly manifestations of the benevolent Shintō divinity of water. But it also refers to a wide variety of mythological and magical creatures found in lakes, ponds, springs and wells, including serpents (snakes and dragons), eels, fish, turtles, and the flesh-eating kappa.
The observances have the significant role of exorcism of bad spirits and purification, especially aimed at dangerous epidemic diseases and water-related disasters which commonly happen during the summer.
Following a ceremony in the neighborhood shrine, the local men carry the mikoshi (portable shrine) to the accompaniment of flute and drum.
It is taken down to a boat waiting at the river’s edge. One boat carries the mikoshi, the musicians, three priests, three boatmen while a second boat carries a group of young men and several ceremonial bamboo, gohei (a ritual wand) and sakaki (Cleyera japonica) branches.