i was gonna say trans aventurine but that’s canon actually i work at hoyoverse so i know <333 other headcanons:

• aventurine loves kpop especially 4th/5th gen girl groups i actually have a playlist of kpop songs i think he listens to while he works. maybe i’ll post it if people are interested
  
• aventurine probably has a kids show that he secretly really likes and collects merch of. and no one knows about it not even the few people who have been to his house because he keeps it in a separate room. hes the epitome of working adult with secret fandom hobby. (this is totally not inspired by miles edgeworth steel samurai fan)
• aventurine didn’t want the cat cakes at first and refused to give them names (he would just call them snack #1 or snack #2 or something).. because he doesn’t want to get attached because he doesn’t think he’s qualified to take care of a living thing. he works all the time and besides he hasn’t had family in so long, he doesn’t remember how to care for someone else (or so he thinks). topaz is probably the one who convinces him to name them because she’s very adamant about pets having names. after he names them he begins to grow attached
• (cw disordered eating) this kinda has its basis in canon but aventurine has a weird relationship w food where he’ll either overeat or not eat anything at all.. like even though he’s so rich he probably trains himself to finishing everything on his plate if he’s at a dinner gathering or something because he can’t get rid of the mindset of not wasting food. on the contrary if no one makes him eat he’ll also just forget to eat and he’s good at ignoring the feeling of hunger too. topaz or ratio has to drag him out for a meal

ok i guess these ended up being somewhat related to canon after all LOL