Let's say one of them gets sick--not to the point of being hospitalized, but maybe a cold or a flu. How would the other two try to care for him? (By the way, I just finished season 1 the other day. Such a cute show! I was already on the En x Atsushi train from the first couple of episodes, but after the finale, I couldn't help but want to include Kinshiro as well. I'm so glad to have found others who ship the three together!)
(My answer for this question got a little out of hand so I'm sorry about the length...! I’m just so glad to see someone still interested in this ship in 2023! it was a lot of fun to think about these three in depth again. I too was a big En/Atsushi fan early on but their dynamic as a trio was undeniable!!! If you have any other questions/thoughts to share, this ask box will be open for them!!! In the meantime, I hope you enjoy these rambling musings of mine :] )
I imagine En, who is lethargic on a GOOD day, would be the biggest baby of them all when he’s sick. 100% doesn’t even try to leave the bed, just whines until Atsushi or Kinshirou agrees to stay with him / feed him his soup / give him a gentle shoulder or head massage to help with his headache, etc… Atsushi is, as always, the mom friend, so I imagine he’s more than happy to acquiesce, and has a very involved soup he makes from scratch whenever any of them is sick, and he makes it while Kinshirou’s on babysitting duty. Meanwhile, Kinshirou: he may act cold or above it all at times, but he’s a natural worrywart. You probably haven’t gotten to that part of the series yet so sliiiiight spoiler warning (although I’ll keep it pretty vague), but in season 2 his somewhat excessive worrying about Atsushi is actually a pretty big plot point! So, I imagine that kind of behavior definitely comes out in full force when En is sick. Kinshirou would be the most genuinely upset of them all (including En), fussing and fretting while Atsushi laughs from the kitchen and tells him En will be just fine and that he’s definitely being a big baby / exaggerating how bad he feels because he knows Kinshirou will fawn over him (and he is right. He’s known En longer, so he’s quite familiar with his antics!). If medicine or groceries need to be gotten, it’s always Atsushi who goes: Kinshirou doesn’t want to let En out of his sight.
Usually, Kinshirou is the first person to chide En about his laziness being a bad habit, so you’d think that in a situation where that laziness (and accompanying whininess!) is upped, there would be a lot more scolding, but it’s quite the opposite: on a normal day, En isn’t doing much by CHOICE. When he’s sick, he can’t help it, and Kinshirou becomes much more accommodating because of it. He may know En doesn’t REALLY need to be treated so gently, but he treats it as an excuse of sorts to be as soft and obliging to En’s whims as he wants, since he would normally encourage him to be more proactive and do things himself for his own good. Basically, En being sick is an excuse for Kinshirou to be doting and spoil him a little, almost as if to make up for being a bit of a (loving) hardass on regular days! En, for his part, absolutely loves it of course.
En I feel would bounce back the quickest out of the three of them, so it’s almost never a long affair when he’s sick, but he does drag it out a bit because he likes when Kinshirou is soft with him, so he might play-cough or complain a bit for the next week after he finally recuperates to score some bonus cuddles and kisses.
Now, when Atsushi is sick: he tends to try to diligently do his usual chores/work, but quickly is cowed when En and Kinshirou team up to force him to REST. He’s conflict avoidant to a fault: if his boyfriends say he’s going to lie down, take his medicine, and nap until he sweats out his fever, who is he to argue? He’s definitely the best cook between the three of them, and his get-well-soon soup is a bit complicated/involved, so early in their relationship especially, they’re not quite able to tackle it alone. If he’s well enough (according to them), he might be allowed to sit at the dinner table wrapped up in a thick fluffy blanket and walk them through the steps, but if he tries to help at all (“Just let me dice the vegetables, it barely takes any strength!”) he’s quickly met with a glare from Kinshirou and a disabling octopus-hug from En. If he’s truly under the weather and can’t manage that, I’d say Kinshirou is quite capable of making Atsushi something comforting and tasty, since he canonically lives alone I believe (and thus has presumably had to cook for himself on several occasions). En becomes the human teddy bear on such occasions, providing constant calming comfort as Atsushi lets his diligence slip for once and openly wallows in his misery a bit (definitely not to the same degree as En does, but still). Once he’s fed, watered, and medicated, Kinshirou joins their little cuddle puddle, as fevers and illness tend to make Atsushi dwell on the pains of the past, and Kinshirou’s presence in particular helps keep the bad feelings at bay (he’s there, he’s WITH Atsushi, they’re not apart, things are so much better now, etc. etc.). Atsushi I picture kinda going from 0 to 100 quite fast, so one day he’s feeling bad and the next morning it’s almost like it never happened. He always wants to throw himself back into the swing of things right away, but of course, Kinshirou and En are having NONE OF THAT, and force him to take it easy for a while longer before they deem him well enough to be left alone.
Kinshirou is a different beast entirely. He’s more disciplined than anyone else they know, and so even En and Atsushi would be hard-pressed to identify when he’s started to feel ill before it starts getting out of hand. He hides his truest pains well, and is reluctant to show weakness even now, when he knows logically that he has people who love him and who he can trust with the fragile, needy parts of himself. Deep down, he still feels it would be asking too much of them to bare those “ugly” parts of himself and expect them to care for him and take them in stride. He sometimes doesn’t feel deserving of their attention when he’s not giving something back, even when he’s at his lowest and has nothing TO give back. Memories of how he behaved towards them for so long embarrass him still, and he sometimes bitterly thinks he was just /lucky/ that they could still love him even after they saw him at his nastiest and neediest, and that he has to do all he can to make sure his luck doesn’t run out. These negative feelings are only exacerbated by his feverish state when sick, which makes it hard to think straight. He worries that acting anything like he did then, wanting or demanding attention and care beyond what they freely give him, being /greedy/ for it, will make them think of how he was then like it always makes him think of it. When he is sick and frustrated and snaps out of pain and exhaustion, he thinks of himself as he was, and he doesn’t want them to think of him that way, so he’s reluctant to reveal it at all, and presses on as normal until either they notice on their own or he simply can’t go on anymore and it FORCES them to notice (often because he passes out from sheer exhaustion). And of course, every time, they prove his worst fears wrong, because they DO love him, and they DO want to care for him and make his hurt better any way they possibly can, no matter if he’s a little short with them.
Once his diligent, poised facade is broken, I imagine Kinshirou to be the weepiest and most miserable of the three when sick (compared to En, who mostly just whines about any and all discomfort and pain and doesn’t want to deal with anything, and Atsushi, who is more easily comforted and rarely falls into sadness spirals). He spends so much energy and time keeping his feelings in check, whether for the sake of his duties or out of personal preference (or those misguided feelings of obligation to be “perfect” for En and Atsushi), that when the dam breaks, there’s just that much more ready to flood out. He cries quite a bit, often quietly, sniffling miserably and hiding his face in whoever’s neck is closest, and so water and electrolyte drinks are a big must. One of his boyfriends absolutely MUST be with him at all times (although that’s basically par for the course when any of them is sick), though he will sometimes blearily insist that he’s okay and that En and Atsushi can leave him be and do whatever they have to/want to do (as if they haven’t dropped anything and everything already from the second that they realized he needed them). Atsushi will still make his Amazing soup, but he might rush it just a tad, because he can hear Kinshirou crying for him from the bedroom, all warbled and wet, even as he snuggles into En’s embrace and grips him as tightly as his sickness-weakened hands possibly can. They’d set him up in the kitchen like they do with Atsushi sometimes, but when he’s sick enough to need help, he’s too sick to sit up straight, so they may sometimes have to resort to something silly, like having their phones open on a call so Atsushi can talk to Kinshirou easily from the kitchen and reassure him from afar with his vocal presence. Feeling abandoned is the absolute worst possible thing for Kinshirou, especially when he’s sick and vulnerable, so even when he sleeps (usually fitfully), both En and Atsushi want to be there, because once early in their relationship he woke up to neither of them in the room (Atsushi was at the store, En was puttering around the house looking for something to entertain Kinshirou with when he woke up) and the resulting heartbreak when a delirious Kinshirou thought they had disappeared for good was too much for them to bear. For a while even after both of them had returned, he was completely inconsolable. They’d rather die than let him go through that again. (Of course, they wouldn’t simply forget that that happened afterwards, no matter how much Kinshirou would like them to. They talk about it, about the still-underlying insecurities and fears that plague Kinshirou (evidently deeply enough that he believes the people who love him may turn on him over essentially nothing), and they work through it together. It gets better over time, with patience and love :] )
Kinshirou is the one for whom sickness tends to linger, so even when he’s well enough to go back to school and his duties, he will likely still be a bit fatigued and sniffly, so En and Atsushi remain clingy and overprotective until he’s in tip-top shape (and honestly, probably a bit after too. It never hurts!)