It seems you misunderstood the story a little, he was not shaming Futaba and Kou always knew his feelings for her, the problem was that Narumi dragged him.down as he was moving on from his mother's death. He felt guilty for thinking about her less and feared that a relationship would harm her. It had nothing to do with Touma but his own trauma and Touma rushed her into a relationship because he saw Kou trying to fix everything.
As for the festival, he didn't have her number and couldn't reach out to her we see in his pov chapters Kou thinking he wants to make up to her.
And Touma deliberately took advantage of her vulnerability for his own benefit, forced her into a relationship and refused to accept a no as an answer. You glorify Touma whilst villainising Kou
Explain how i misunderstood the story, i know he knew his feelings but the thing is he didn't show it. He always initiated things and reminded futaba of their past only to see her reaction and for her to accept that she still loved him for later to say that he doesn't like her, he only wanted to feel that he was loved but not give back. Let's not use his mother's death as an excuse a lot of time had passed for him to move on and while he might have not it was expected of him to do so after giving futaba hope of being with him and not just straight up ignore her for narumi. He has given narumi more than enough, for once he could have chosen futaba. But still to call kou not getting in a relationship with futaba trauma and using it as an excuse to justify her choosing to be in a relationship with touma is stupid. He made sure that she wasn't thinking of kou when she made that decision not to mention she knew he was to good to be missed and that's why if there is someone holding someone back that is futaba herself. She was the one who wanted the world that touma showed to her, she enjoyed it too but never gave anything in return and while touma didn't want anything from the current her who was still getting over kou he could expect of her to at least be away from him or at least not be influenced by him. But lets be honest futaba never did this she only made excuses and told lies. Her lying to herself is what brought her here and the moment kou through some sentiment feelings towards her she immediately took the bait, not showing the tiniest respect for herself in making him repent more or touma the one she was in a relationship with.
And where was it stated that he didn't have her number
Futaba is an idiot, kou wasn't true to what he felt (i understand in narumi's arc( not really)but why wasn't he at the start) he was acting so mysterious and was shaming this girl as if it was his job or something(how funny, seems like a joke at first but when you grow up you will realise that those joke's weren't as funny as you thought). Selfish for realising your feelings for her after seeing her with another guy(blocking her way even after you broke her heart by being with the other girl at the end of the day only your feelings mattered). If kou wanted to leave he could leave even if everybody was hurt, if kou wanted to stay everyone would need to oblige and cater to him. That girl that is the mc friend that had a crush on kou clearly wasn't a friend, if you see your friend getting treated as a side girl and the only thing that comes to your mind is her not loosing because you lost to her and not her feelings even after you saw how he was with the other girl seems like a not so reliable person, she even made a face when kikuchi was actually doing something for the mc to feel better but the only thing she saw was someone getting in the way( the least she could have done was scold kou but she turned to futaba as if it was her fault). Kou had many chances but he didn't take them when they were given(how can you love someone like this i don't know), the only thing this character had going was him loosing his mother. Also at the festival(or shrine or whatever)when he didn't meet mc why the hell didn't he text her that he wouldn't be coming but he let her wait there until late as an idiot and he didn't even say he was moving(and i'm sure divorce procedures don't just happen overnight). The other two friends where a little better(but they went from a good approach to one that they felt as if they were guilty about), the guy that scolded ml was right he shouldn't have gone along with narumi's act and the girl that stopped the others from saying kou's name around fl while making sure he didn't approach her were completely right but how did it end in them feeling guilty(it was right of them to tell someone stupid off, as they supported him at the start, they could say no at the end). Kukichi being manipulative? this couldn't be more fare from the truth. He made it clear that he knows her true feelings he will eccept them as they are but with her putting efforts in forgetting kou(even if not at least while trying), and that he will never give up that means for her not to break up with him. He was to nice, to good and that made me realise that in a story that has characters with so many flaws he was way out of their league, an untouchable rose with a nectar that would drip for anyone that would need it, he would share his warmth and shine even brighter then the sun. But even after they tried to cut his stem he was still smiling at them ever so brightly, nevertheless i hope that you will grow some thorns so you won't hurt anymore. For the people that say well this is reality, then let me tell you it's not, cause there's no way anyone would let you act so desperate and cling to a fool not only that but they would beat some sense in you and show that you are actually worth it( at least this is the normal reaction that people should have). Well you can suffer if you want, but i suggest you look behind and see who else is being hurt by seeing you suffer while you try to reach for such a small amount of love when they are giving you the world.