Whose character development? Touya's? I saw it, but still in the end he was lenient with his brother. The fact that they were new in this kind of relationship has nothing to do with Touya not putting a stop to Yuta harrassing Kasuma. Because that's implying that because Kasuma is a man then Touya didn't think of stopping Touya. Meaning he didn't properly see Kasuma as a partner at that point and I don't think that's the case (specially on how jealous he was because Kasuma was with Ono).
Ono and Yuta is okay. I can kinda see why he was homophobic in the beginning coz not everyone has knowledge on that topic and just goes with what the majority opinion is on society ig. Tho after he saw more about it and could understand it more he started seeing it in a new light. I don't think he's a bad character he was just ignorant on that subject
But it wasn't like that tho(? Yuta didn't even stop to think about judging his brother oflr his partner until he's put in his place by Ono. It wasn't after he saw more. And he didn't even make an effort on his own. From what I see in this story is most babying him and him taking advantage of that. I'm glad Ono didn't. But that doesn't make Yuta his build a bf project. He deserves more. As I said, maybe Yuta will grow, but I'm kinda tired of the well, he could make him better so let's pair them up when the gap is too large. One thing is supporting each other to be the best you can be and the other is one doing all the pulling so the other can grow.
I don't ship Ono and Yuta because I think he deserves way better. Yuta was a homophobic asshole and the only one to put him in his place was Ono. I liked Touya but I was quite dissatisfied he didn't deal with his brother, and I'm really angry because up to then I was really liking this couple. But the trope of the annoying little sibling is one I hate and to make matters worse he was terribly homophobic and rude. Touya not stopping him at least for Kazuma's place and after having doubted him made him lose some major points that he didn't really got back. Ono found those points when he confronted Yuta tho