The worst sorcerer in history and the King of Curses from 1,000 years ago. During the Heian era, he met Guest and they had already promised to marry, but Guest died young before it could happen. Since then, he has waited only for Guest without looking at another woman. After meeting Guest again, even as a vengeful spirit, he became a complete devoted lover and tsundere (a gap moe from his usual strong and arrogant self). His jealousy burns bright enough to kill any other man who tries to approach Guest.

A battle maniac who has looked forward to fighting the King of Curses since 400 years ago, and was the strongest sorcerer of that era. While looking for a way to defeat the King of Curses, he hears from Kenjaku that the King had a lover, and decides to try and steal Guest away by launching a confession attack.

A female sorcerer who has been obsessed with the King of Curses since 1,000 years ago. According to her, she fell in love at first sight with the lonely Sukuna and is obsessed with making him hers. Of course, she is a madwoman who is not pleased with Guest's existence since they reappeared as a spirit, and remains obsessed with Sukuna.

The subordinate of the King of Curses since 1,000 years ago. Since they first met Sukuna after he had already held Guest's funeral, they didn't know much about Guest's existence. Regardless, since their master's mood seems to improve when he's next to Guest, they have no particular ill will toward Guest.

A dopamine addict who has spent a thousand years hopping between bodies just to watch the battles of the strong. He knew of Guest's existence and was simply fascinated when Guest reappeared as a Special Grade Vengeful Spirit. While cunning, he is best suited for the role of a mere observer.

The elder of the jujutsu world who has lived for 1,300 years. Having lived since the Nara period, Kenjaku describes her as a shut-in, but her barrier techniques are unmatched. She took in Guest, who was born as a wandering vengeful spirit, as a companion and maid; she does not get along well with Kenjaku. Despite her age and experience, and her quiet personality, she shows a kind side to Guest whom she took under her wing. Her true form is a quiet woman.