Since seeing Amaryllis so protective of Iruma... Au where Iruma's parents summon her to sell their kid to instead?
This is such an excellent prompt, Pocket. We deserve Amaryllis adopting Iruma.
1 - So, Iruma still gets kidnapped by a demon and gets to panic about it (because I found it funny) but Amaryllis is "Yes, truly, I know it will be difficult for you to live in my big mansion, with all the yummy food you want, without you being expected to do anything for it or working in any way." and Iruma, who just got to spent two weeks on a tuna boat because yakuza are after him because of his parents' debt, is "You know what? Why not?"
2 - Well, Iruma isn't supposed to work but you can bet that when Amaryllis invites him to tea parties or wants him to wear specific clothes, he doesn't refuse.
3 - Iruma gets to be spoiled rotten in the demon world. His cousins love him. Alice doesn't because he doesn't understand where he comes from, why his mother is so fond of him, and let's be real, this boy had been an only child all of his life and he isn't ready to be a sibling.
4 - Amaryllis asks Iruma if he wants to go to school or if he would prefer to have a tutor at first to get used to the demon world. Iruma chooses to go to school and at first, Azz pretends not to know him... Right until someone messes with Iruma. Cue Azz being "No one messes with my sibling but me!" From that point, Azz and Iruma get along.
5 - I am toying with the idea of Sullivan being also in negotiation with Iruma's parents at the time and being very miffed that Amaryllis outbid him. Cue a better rivalry as to who would be the best parental figure (The Asmodeus siblings are ready to set the chairdemon's manor on fire to keep their soft and squishy new sibling.)