Under the moniker of the One-Eyed Owl (隻眼の梟, Sekigan no Fukurō), he repeatedly tried to cover up for the real Owl's behavior. When they had realized that there are two Owls, the investigators began to call him the Non-Killing Owl (不殺の梟, Fusatsu no Fukurō).
The One-Eyed Owl is the offspring of Yoshimura and a human called Ukina.