The River Festival and Rain Ritual have been held on every Sunday around July 20.

The local residents put "Gohei" (sacred Shinto paper streamers), egg plants, and cucumbers at Koshi River by Sumiyoshi Hiyoshi Shrine so that the Kappa (water sprite) won't cause flooding.

The Rain Ritual is believed to have begun when the ruler Koshi Takakado played the Taiko Drum to help local people suffering from droughts.