Oushi, was the childhood friend. That’s how he was introduced and that’s how it stayed and for good reason. Yes he learned sign language to communicate with her. Yuki has said many times “he is actually uses it to be mean to me”. Yes his intentions were good but intent vs impact. It doesn’t matter if it was from a kind place that’s not how it’s always received because that’s not how he delivers it. He went into her world and feels entitled to it. Oushi assumed learning the language was enough to grant him a closeness to her but, even than they barely talked and most of it was to berate her. Any chance he had to push her back in that bubble he did. Oushi; underestimate her in every category of life, used sign language to control how she interacts with the world around her, questioning her choices in friends, say that (all deaf people - ableist ) should stay in one place, acting as if itsu would never like her genuinely. Yes I understand he doesn’t want her taken advantage of but, he takes advantage of his skill to limit her world constantly. Every time he talked to her was an attempt to make sure she stayed with in the confines of her world that only he could access. Yuki chose itsu for a reason example: When itsu and Oushi were talking outside the bar. Oushi’s request was for itsu to dump her. Itsu made it clear her likes her, he would always choose her and that a break up is mutual. Itsu, respects, care for and sees her as a person. Wouldn’t allow himself nor Oushi to decide how yuki’s relationship will go. Oushi on the other’s hand has nothing but good intentions but lacks; respect, maturity, and is entitled. Under no circumstance has Oushi done anything to warrant romantic feelings from Yuki. He doesn’t just get them because he learned sign language. He doesn’t get a pass on his piss poor communication skills because he can use sign language. His character as well as Emma’s character was to show a few things: Childhood friend trope only works if it’s mutual, that history with a person doesn’t mean you can push pass their boundaries, and waiting around until someone has no choice but to pick you is as pathetic and manipulative as it sounds.