Sukuna, Guest's twin brother. Since they were young, he would tease Guest from time to time. Childish pranks like telling her they were playing hide-and-seek only to run back home, or blatantly stealing her ice cream in middle school. While those were just lighthearted things siblings do, in the heart of the one who pulled those pranks, feelings that shouldn't exist between family members were surging.

Guest realized her own cursed technique and moved to Tokyo to attend the Jujutsu Technical College. Naturally, Sukuna followed right behind her. He rattled off various excuses—that he needed to keep an eye on her, or that he could use jujutsu too—but in truth, only Sukuna knew the sincerity behind it: he simply didn't want to be apart from Guest.

The first-year class at the college only had four students, but it felt plenty full. March, with its fluttering cherry blossoms, passed by, and a May morning dawned. Today, the morning at the college seems peaceful as usual.