thinking about shane hollander and being mixed-race and assimilation and culture loss...
yuna mentions in ep1 that hockey is something that made her feel like a real canadian. to me this suggests two possibilities: a) she might be an immigrant herself, one who came to canada young and assimilated as a child, or b) her grandparents were the ones who immigrated; her parents, born in canada, experienced japanese internment when they were young, and therefore pushed her hard to assmiliate because they keenly felt the consequences of being othered and didn't want that for her.
either way, i think this leads to yuna raising shane in a sort of mixture of cultures. i think she's proud enough of being japanese that she'd want her child to speak it, especially given that as he gets older, him being visibly asian in hockey is clearly something meaningful to her. i also really like the idea of david trying to learn japanese for her (he's not fluent - just vaguely conversational - and she often tells him his accent is atrocious, but she's very fond of it).
that said, shane vs intensely white hockey culture and the pressures of being mixed: too asian to be white, too white to be asian, too other to be either. his coping mechanism is to try his hardest to assimilate, to be normal in the locker room and with his classmates: no "weird" food in his lunches. only calling yuna mom in front of his white friends, instead of kaa-san like he says at home. asking her not to say shane-kun in front of them because they'll tease him and think it's funny.
but the thing about assimilation is that no matter how white you try to act it'll never be enough. it's about taking your culture for granted and not realizing what you're distancing yourself from, until you're left grasping for what of it you have left, because you finally realized that you will always be an outsider anyway. i think that's something that finally hits shane once his pro hockey career gets into full swing, when he's around 20 or so, and it hits him that he used to be fluent in japanese as a child, but he's lost so much of it over the years because he just... stopped speaking it.
so that's when he starts trying to learn again, and starts talking to yuna in japanese more again, and picks up some books in japanese, and maybe watches jdramas or anime on planes. because he's in the nhl and he is The Asian Guy and no one has ever let him forget it, so what's the point in trying to run from it when it's just him and the silence? he used to be fluent when he was a little kid, and it hurts to realize how much he's forgotten.
of course, because of who shane is as a person, this is a very private thing. he still doesn't really speak japanese outside the family, and it's a significant mark of trust when he answers a phone call from yuna in front of hayden and jj and greets her as kaa-san, not mom. he doesn't bring japanese food when he packs his lunches because he knows he'll be eating in front of his white teammates. he compartmentalizes (what's more shane hollander than compartmentalization?).
ilya actually has no idea that shane speaks japanese until the cottage because shane just. doesn't. it's a sign of emotional vulnerability and trust and for so long, shane wasn't sure how emotionally vulnerable he was really allowed to be in front of ilya, not after sochi/vegas 2014 and everything that spiraled from there.
but then they're at the cottage and shane's got hockey books written in japanese (translations of books he's already read in english, mostly) stacked on the coffee table, and shane's snacking on salted nori (he's happy to offer ilya some, too), and there's some of yuna's old cds of 80s jpop sitting by the speakers, and ilya realizes that huh. there's a whole other side of himself that shane has been holding back this whole time. and now he's finally letting ilya see it. and that means more to him than he can really put into words. (so obviously they fuck nasty about it.)