he said so much about 'he dont want to think about himself only' but insteed didn't he just do that? He push back him and said 'I WANT to think about it' 'I WANT distance between us" while Nao try to considerate it together. Not only homo couple have isue like that (speak about myself tho)
saying "I" was what taichi did wrong he didn't speak what he really thinks, he didn't said he wanted a distance between them because of he wished nao the best I'm not saying taichi isn't at fault at all but he was only thinking of nao he thought it was the best and now he realized his mistake plus I know it's not something only gay couples have that kind of problems but you know they have it tough
all taichi wants is nao's happiness but he didn't realize nao was already happy with him until someone else comes in the picture. The meeting with his mother is opened his old scars and made him question everything, he saw how good is nao with kids and how a good father he would be and how it's not something he could give to him the way he did things was wrong but what he wanted was a good thing he wanted to put nao at the first. I hope they will have a good talk and fix their problems.
And about nishina since the very beginning I didn't like him and I still don't and yes the main reason is he try to come between nao and taichi but one of reason is at the first he told to nao a relationship between two man wouldn't work and always have an end I know he said it because of his partner cheated him but still he wasn't believing and why he keep try to be close to nao when he perfectly knows he is in love with someone else? I don't like that type of characters but I still do wish he would have his own stroy and find his happiness but not with nao