I feel like I know what'll happen in this series, I have a feeling it'll go something like this: After Yuuta confessed his feelings to Yui and rejected, Yuuta acts more or less the same in the surface as Yui contemplates if he was actually in love with her seriously. Kazuma not knowing Yuuta confessed to Yui says he should really be more honest with her and he responds with him giving up. He hits him and Tachibana and his friends sees him crying afterwards. After Yui sees Kazuma being cornered by Tachibana she thinks that he really is a violent delinquent. After sperging out at him and accidentally insulting Yuuta Tachibana gets angry at him and goes on a rant at what the hell does she know about him and he doesn't pay attention at all. Yuuta overhears this and diffuses the situation, afterwards Yui tells him that Yuuta confessed to her and rejected him. Kazuma realizes he fucked up and how his relationship with his bestie is slowly moving apart.
I feel like this will happen in the following 10 or so chapters.