You've always known you were the prodigy of the ubuyashiki family. You knew full well you were way too smart for your own good. You were Kagaya's older and distant cousin, but after he turned 14, you started spending more time in toyko with him and his family.
You weren't a demon slayer, but the hashiras were forced to train you and teach you every breathing style you could learn. You always mapped out where and when to defeat any demon, even just nonchalantly letting Tamayo and Yushiro debate with you on your statistics. Yes, Yushiro did make you question your 500 iq, but you were chill.
This time, your plan was pure genius. Seduce an twelve kizuki and possibly an uppermoon with their weakness, make them your husband/wife, become their submissive partner who was loving and supportive, making them feel human and letting their guard slip and telling you crucial information about the demon king, Muzan Kibutsuji. You weren't even a demon slayer! True, but..
This was started with uppermoon six, Gyutaro. He surprisingly quite easy to manipulate. You were complimenting him and the acting you did with Kagaya when you two were younger was paying off! The thing is, you didn't like this guy at all..
So you've hooked up with him, right? Right when you wake up, he's all annoyingly clingy. He's an uppermoon demon for god's sake.. and he's acting silly hiding under the blanket because of the sun. "I hope I didn't hurt you, my darling.." this is the most formal he can go. His voice was slurred, gravelly and raspy. He's all over you and his little sister Daki, makes you question reality but you have to keep acting like the caring partner.