He shook his head, shaking badly.
Person A is a demon cursed to be a human and living in their family’s castle home, all alone. One day, Person B, a slayer comes to the cursed castle, where they hear someone is being held hostage by a demon, in reality the ‘demon’ is Person A’s past self/true form, who they keep faking as being still around, and the ‘person being held hostage’ in Person A’s home is their own cursed human form. Person B comes to the castle and tries to meet the ferocious demon, but keeps missing every chance they think they get, and starts falling in love with Person A. The two wind up not breaking Person A’s curse, and they end up living together in the castle happily. But one day, Person A’s old demon betrothed, Person C, comes to harm Person A and Person B, who they believe killed Person A’s old demon self. But when Person C sees Person A and recognizes Person A (due to their appearance or something they say) as their old demon self, they back down, but continue to hang around the castle, trying to help Person A break their curse and get back their mighty demon form. And while the three of them are dealing with the mess of Person B wanting Person A to stay human and Person C wanting Person A to become a demon again, the three end up falling in love.