LOWKEY this set of outfits could be a banger au hear me out: candy workshop
like imagine emu is a princess who’s candy themed kingdom resides in the clouds and one day one of their major air-transport machines stops working so they have to enlist the help of rui, who specializes in machines creation and repair!!!
and rui is also famous for making all sorts of machines that help the people in their daily lives. home helpers, cooks, idk sentient washing machines.
but all that matters is that rui is a mechanical genius that is hired to help the otoris. (maybe his parents helped start his business and caught their attention years ago? or had relations with the otori parents early on?) ((maybe they helped create the sky/air machines the candy kingdom use))
anyways, nene is, of course, paired up with emu as her butler of sorts? or maybe trusted friend/advisor? she knows the otoris well and is entrusted with emu’s safety and with the task of reigning her in when she gets too excited. otori brothers feel calmer when nene is there with emu lol
tsukasa is rui’s assistant who also comes up with flashy ideas. he saw the happiness that rui’s machines brought to the people, and decided that he wanted to work with him. SPECIFICALLY rui’s machine aided saki while she was young and it left an impact on him, so he wanted to “repay” the favor.
kaito’s just there lol. “what purpose does he serve?” um idkk :3. we could always go the traditional route with virtual singers and make him a spirit of sorts…
ANYWAYS YEAH AU IDEA MIGHT BUILD ON IT BUT JUST A THOUGHT