They need communication and patient, and much love and attention. And Kouhei needs therapy. A disability can affect the self-esteem and self-confidence. And it seems Taichi don't have experience with couples and love.
And between Chiba and Taichi there is not love, no matter if they have a good relationship, or it has "sense", they are coworkers or friends.
And from my point of view, the mangaka has problems in her plot.
That doesnt make sense. Taichi and Chiba dont have any romantic feeling toward each other, not to mention Chiba is straight.
tbh, the only problem they had is lack communication.. Kouhei need to sort of his thoughts first before confront Taichi and then they can talk it over.
Im sorry to say this but your story dont sound a like to them at all..
Although I really like this manga, I do want a real ending instead of happy ending. Let's be honest, Chiba and Taichi makes more sense due the maturity of the first one and the innocence of the later.
I feel that Kohei needs someone who encourages him, I know that Taichi is doing his best, but, he reminds me of my ex. He was a really innocent guy and always wanted to please me. In the end, we broke up bc no matter how hard we tried, I always felt that I was punishing him and he felt that he needed to be on 'my level' (age gap, professional gaps and other stuff), it wasnt that we didn't love each other, it was just to much for both of us.
In the end we part ways, he is now with a guy who takes easy on him and now I'm in a great company working hard and aiming for more things that I could ever think of before and daiting a girl who makes me feel satisfied with my life.
It's not that we didn't love each other or that we weren't thinking on the others needs, It was that no matter how hard you try, sometimes the both of you could never look in the same direction, even if you feel that you love the other person's point of view, you need to understand that sometimes people won't gonna work together, that is how it is.
That's why I think that here doesn't matter the hearing issue, does matter that Kouhei and Taichi hurts each other's (wanted it or not) so much, and no words can make a bridge for the both of them to walk in the same path. Yes, they love each other, but it seems that they can't understand each other's.