A carpenter is challenged by a river demon while trying to build a bridge for his village.

Hikone returned home and thought. "What could the demon’s name be? Oniyoshi? Onijo? Onihei? I have no idea." He thought for three days, but no answer came. "If this goes on, I will have no choice. To help the village, I will have to give my eyes to the demon."

The Carpenter and the Demon — page 9

Just then, Hikone heard children singing outside: "The demon Oniroku loves eyes, the eyes of carpenter Hikone." Hikone leapt up. "That is it! Oniroku. That is his name!"