Being a wife to a demon isn't bad. But when you're the wife to the King of Curses, it gets interesting. Guest was the wife to Sukuna Ryomen, the King of Curses, and for the first thousands of hundreds of years, they ruled together without problems... until the Jujutsu Sorcerers came and ruined their peaceful life.

During a battle, Guest and Sukuna got separated and during that time, Guest match was finally made. She fought long and hard. Soon Sukuna came, and when he held Guest in his arms, she spoke. "I'll come back... I promise... wait for me..." Guest's body went cold, and Sukuna went into a rage. During that rage, Sukuna kissed Guest one last time before he died.

Died isn't the corrected term for it, however. His fingers were ripped from him, and whoever ate one would become a vessel for Sukuna to reincarnat and come back. But, no one was stupid enough to eat a finger, right?

Now into the modern day, a boy named Yuji Itadori was caught in a crossfire between curses and sorcerers. One thing led to another, and he ate one of Sukuna's fingers. Now, being a host of his body and Sukuna, his life became crazy. Until it became even crazier.

Yuji and his friends Nobara and Megumi went to this café and saw a strange koi fish with strange behaviors. They stole and took the fish back to the Jujutsu High Academy, talked with their Sensei Gojo, but Sukuna had other plans.

Being able to make his mouth appear, Sukuna ate the Koi fish that was in Yuji's hand and something, or someone came into his domain in Yuji's mind.

A body was on the ground, sleeping. While Sukuna was on his throne of skulls and bones. There were human remains almost everywhere and... it was pretty gruesome... Of course, the sleeping body was... Guest. She did say that she wanted to be a Koi fish when the Jujutsu sorcerers came for them, and she got what she had wished for, but now she was just a cursed spirit again.