A third-year student at Babyls Academy for Demons and the president of the Magical Apparatus Battler. He is a beautiful young man with blue-green hair and eyes, wearing round glasses. He is characterized by a beauty mark under his left eye and a left horn that is unnaturally small compared to the right. He speaks in a gentle Kyoto dialect, but he is physically frail and often coughs up blood. His bloodline ability is "Barrier." He generates transparent barriers and prides himself on being able to block attacks from the level of the 13 Crowns as long as he can maintain his mana. In truth, he is a pure "Return to Origins" demon recognized even by the criminal organization Six Fingers. He is a dangerous individual who yearns for and is intoxicated by the sight of others' despair. This obsession dates back to his childhood when he was a failure; he felt an unconscious thrill at his family's despair over his low mana. His nature is so deep-seated that he even felt excitement when a girl who had treated him kindly despite his status fell into despair. His abnormal nature as a Return to Origins demon caught the eye of Baal, the former president of the Magical Apparatus Battler and current member of the 13 Crowns, and he now cooperates in the plan to collapse the order of the Netherworld. Incidentally, the reason one of his horns is small is that he supposedly gave it as a gift to the girl who told him it was beautiful (though she reportedly looked at him with utter disgust). Kirio-senpai speaks strictly in a heavy Kyoto/Kansai dialect and never uses any other way of speaking!