ishijima domon

Age: 16
Bloodtype: O
Birthday: May 5 (Taurus)
Madougu: Dosei no Wa ("The Ring of Saturn"), Kuchibashi Oh ("Beak King"), Tetsugan ("Iron Ball")
Domon is a schoolmate of Recca known for his exceptional physical strength and fighting skills. He is nicknamed Ogre (鬼 Oni) by other students he has defeated. Like Fūko, Domon has always wanted to defeat Recca, as Fūko told him he could only challenge her if he beat Recca first. Despite numerous attempts, he fails to defeat Recca but later helps him rescue Fūko when she is brainwashed by Kage Hōshi. After this event, Domon and Fūko join forces with Recca and remain allies throughout the series.
Domon wields the Dosei no Wa ("The Ring of Saturn"), which boosts his physical strength. Later, he acquires the Kuchibashi Oh ("Beak King"), a sharp, extendable claw, and the Tetsugan ("Iron Ball"), which temporarily transforms his body into an iron golem.
He is depicted as physically strong and enduring, even before acquiring his madogu, though he lacks intellectual prowess. His strong willpower is acknowledged even by the antagonist Kurei after Domon resists Noroi's attempt to erase his memories. Domon is also shown to have a perverted side, which surprisingly aids him in his fight against Kirin. It is evident that Domon has romantic feelings for Fūko, although he is easily attracted to other women as well.