He is a third-year student at the Demon School (Babirus) and the head of the Magical Artifact Research Corps.

He has hair and eyes that seem to shimmer with a bluish-green hue, and he wears round glasses.

Like the mole beneath his left eye, he is an exceptionally handsome young man whose left side bears an unnaturally small horn, making it particularly striking.

He speaks in a gentle, almost Kyoto‑style dialect, but his health is frail, and he often coughs up blood. His family’s innate ability is “Severance (Barrier).”

He can generate a transparent barrier and proudly claims it could even withstand attacks from a 13‑Crown‑ranked demon—if only he could sustain his magical power. In fact, even the criminal syndicate known as the Six Fingers acknowledges him as a genuine, original “returnee” demon.

He is a dangerous individual who becomes obsessed with—and even intoxicated by—watching others’ faces of despair, perhaps more so than anyone else.

This obsession stems from his childhood: when he was a failure, his family grew frustrated and despondent over his lack of magical power. Unconsciously, he felt a thrill at their despair, and he became wildly excited when the girl who had once treated him kindly—though she had been shunned—ultimately succumbed to despair herself.
It was this very abnormality, characteristic of a true returnee, that caught the attention of Baal, then head of the Magical Artifact Research Corps and now one of the 13 Crowns, leading them to collaborate in undermining the order of the Demon Realm.
Incidentally, the tiny horn on one side of his head apparently came about because he gave it as a gift to the girl who had called it beautiful—though she reportedly made a very unpleasant face about it.
Senior Kiriwo speaks exclusively in a thick, distinctive Kyoto‑Kansai accent; he never uses any other dialect!
His first-person pronoun is “boku.”