Hi anon you're so awesome too!!
Idk if you mean them individually or as a ship so I'll do both
Hiyori is actually really blunt and can be genuinely mean but he's careful and kind around his juniors because he likes the senpai role
Jun-kun is very soft to me, I think at this point he's maybe the most peaceful member of Eden? And he trusts them a lot so I think he'd probably go along with whatever he's told to do unless he feels that something is really wrong
Anyway in terms of hiyojun, I think that even if they do things that are traditionally romantic, the kind of love they feel for each other is more undefined? I'm most definitely projecting here but the fact that Hiyori just wants to be close to Jun because he's warm and Jun cooking and running errands for Hiyori feels less like romantic gestures and more like signs of devotion and trust which to he isn't an inherently romantic thing, and tbh I think that's beautiful in its own way
Hiyori and Jun do definitely look at each other wistfully because they both admire each other immensely but they also never actually tell each other that so they end up bickering a lot which is funny
I also like the idea of them as a qpr where they just raise Mary together but then Jun-kun is free to date whoever
Anyway I also think that while polyeden is endgame, hiyojun is the first ship to actually get together
,,, wow this got long uh— I probably have more thoughts tbh but I don't want this answer to be a wholeass essay lmao I hope you enjoy my rambles~