Supposedly, the history of cormorant fishing on the Uji River dates back to the Heian period (794 - 1185). The cormorants, with their sharp beaks and talons, are raised with love and care by usho, or cormorant masters, and are connected to them via a cord when fishing.

Untethered cormorant fishing is a method where the birds are released into the river without using a cord, where they are free to catch fish in the water as they like until they are called back by the usho. This method requires an even greater than usual level of trust between the cormorants and the usho.