I like this manga but the melodrama feels so forced.
Like him not wanting them to be friendly at school because... because, you see... well, um...
Because there's no fucking reason at all for him to act like they aren't friends? Even when it comes up naturally in conversation, he deflects like Sekiro just because she happens to be a pretty girl, and imagine if people knew HE was her friend, oh the horror.
Like I get what the author wanted to do with their private / at school relationship, but there's no in-story obstacle or past trauma or whatever to serve as a setup for that. It's just the MC acting like an idiot from neutral.
His inferiority complex is not a compelling enough reason for him to go to such extremes to deny their relationship. It's undercooked.