Uzuki and the reason of his actions and obsession
Uzuki is a kid that grew up out of touch with his emotions. He has very clear psychopath tendencies. His parents did not provide any kind of emotional support, and he didn't get to develop any kind of genuine affectionate relationship with anyone. Moreover, for him, all people do is lie and hurt other people in order to gain something.
So, when Chika first saves him, he thinks he did it for money. Why else would he have stepped up for him? And so, he was puzzled when Chika just frowned at the money Uzuki offered and walked away.
The second time he sees him, when he saves that child from getting burnt with the cigarrette, and again, he just walks away without expecting a thanks, Uzuki is incredibly touched, cause he realizes Chika's kindness doesn't have a prize, or is for any kind of profit.
He goes meet him to thank him for saving him (and out of curiosity), and Chika once again tries to help Uzuki, by driving him away because that place is dangerous and Uzuki, looking like a guy from a good school and good family, could actually get hurt.
And then Uzuki's obsession starts
For the first time, someone is sincerely worried about him, just out of kindness.
And he wants that for himself.
And so he joins the gang, where he can be with Chika
But the Chika that was in the gang was not the true Chika. He was a boy hurting and desperate for his voice to be heard
And when his gramps hears that voice (and then the koto club), Chika has no need for the fights or the gang. He now has a place to go home to, where he doesn't have to shout out with his whole being by throwing out fists.
But Uzuki has no place in that new life
And he resents and attacks what "took Chika away"
The way I see it, Uzuki created who Chika is as a person, and if Chika changes from that, then that's not the "true" Chika. So when Chika DOES change, and as a result steps away from the gang life, Uzuki is desperately trying to bring him back to who thinks Chika really is.
The Chika he could be with, and whose life he could be part of
And he thinks by "showing" how Chika does not belong to the koto club, he can make him come back
But of course Chika says: "Even so, I still wanna be with them. I don't want to ever come back."
And Uzuki snaps. And is trying to get Chika banned from the club
And Abiko is plain psycho and trying to make him physically unable to play.
Until Satowa has enough and steps in.
I get why Uzuki is doing what he is doing. Chika was his only source of sincere kindness, and he found the contradiction Chika was quite beautiful.
He hit people, but he was the kindest person he ever met. And hitting people was how Uzuki saw Chika's real emotions
In a way, Chika's voice did reach Uzuki, but he didn't interpret it as the shout out for help that it really was. And he won't listen to the real meaning of his shouting out.
But here comes the quote Takinami said in ch 104: "There's people who just won't listen, no matter how much you talk to them"
Because Uzuki is out of touch with his emotions, he tries to just label everything using his own logic and rationality. In his mind, Chika was who he was "Covered in blood and mud, loved by no one and unable to trust nobody". To him, Chika was in the wrong by changing. By going to a place that "didn't fit him", turning into someone that, according to Uzuki, was a lie.
Uzuki is incredibly possessive and arrogant.
He is intelligent, and knows this. He also thinks he knows better than anyone.
In reality, he is unable to understand the real emotions that drove Chika away from the gang and the fights, or his need to be in a place where his voice was heard
He can't understand it, because the place where Uzuki's needs (or one of them) were fulfilled was precisely with gang Chika
So he doesn't get how that Chika is not the "true" Chika. Someone else is turning Chika into a fake version of who he really is.
And he thinks he cannot be wrong thinking that
He is trying to "correct" those wrongs
All and all, Uzuki is darn interesting to analyze. As messed up as he is...