Ryo

...which, of course, is something he told no one about. if anything, he initially tried to get them to think positively about their high school days.

but after they drink some more, he's the first one to start talking about their past seriously

also, if you go back and watch this scene, he's the only one whose face we don't see while jyushi is teasing them with their old pics. everyone else starts laughing at his antics, except karamatsu. in fact, he actually has this reeeeaaaaalllly subtle moment where he hunches forward slightly. like he visibly tenses up a bit (i wish i knew how to make gifs man).

with karamatsu the writers like to take a very “show don’t tell” approach. Yes there are episodes where he narrates (overseas vacation) and that could be considered his inner monologue, but for the most part we kiiinda don’t really know what he’s thinking. especially when he's being insulted. like he straight up either doesn't respond or he just goes "mmmm~~?"

(and as we know, he gets insulted a lot)

the thing is, this is by design. Because not only do we have a direct quote from his voice actor (yuichi nakamura) about it.

we also literally have an entire skit criticizing him for it.

but i think that this tendency to hold things in directly stems from that fight on the roof. The one time he really tried to step out of his comfort zone and approach his brothers about something earnestly, he started the worst fight they’ve ever had.

(also side note, he actually only starts opening up about it after he takes a couple sips from the beer osomatsu got for them)

Now I’m not going to argue with the director over whether karamatsu is a 100% bonafide kind good hearted person or not (though i should note that this was from 2016 and his characterization has changed a lot since then). but i think it's important to note that the rest of them lowkey forgot about that fight while karamatsu consciously held it in because he didn't want to remind them of it and potentially start another fight.

when they discuss their regrets, the rest of the bros are more-so regretful over how they acted as teens. they discuss how their teenage "weirdness" stemmed from their dislike of being sextuplets. this dislike further manifested as a dislike for each other. but karamatsu's regret was over his failure to bring them together. i do appreciate that this strong piece of characterization was based around the love he has for his brothers.

Nothing to do on a Saturday night?