Woah you know when I saw the scene from the raw with her smiling at the MC I just knew that it’s actually him she had a thing for and that he misunderstood it (too many old school yaois had that exact trope), but I can’t read raws so I was just waiting for that to be translated . Thanks for your confirmation. They’re going to waste their high school years misunderstanding this though, which sucks.
Nah, in these types of stories, it just looks like they’re spending a lot of time alone. That’s not the case. The girl probably goes to him to seek advice and have the ML talk to the MC on her behalf. Since he won’t, she goes to the MC herself. Then ML shows up to stop her from confessions. I’m situations such as this, both leads love each other and are convinced the other one won’t see them that way. So it’s natural for him to think that his friend who agree to go out with what appears to be the prettiest girl at their school. This the best the ML believes they can do is cockblock her so she won’t get a chance. And in case of MC, as we’ve seen it already, he has a mean look on his face and walks out on him every time someone new or pretty holds the ML’s attention for a bit.
It just sucks because they’re delaying all the hot couple times they could have together because of misunderstandings, jealousy and possessiveness.
Spoilers
So the MC really, really likes the ML and it's mutual, they later fight because of misujderstandings and jealousy, separate and reunite in college.