Every girl here is just a bitch and the guy is no better. The childhood friend has that obnoxious trait of not being able to handle other people around her love interest and the girl that transfered has the obnoxious clingy attitude, just perfect.
secondly, you’re not wrong. both of the girls are definitely gonna be shitty people who use love as an excuse to justify shitty behavior. and as for the mc, chances are he’s gonna be brainless and end up not realizing the childhood friend obviously has feelings for her and further deteriorate the relationships between the 3 of them. but they most likely will make up in the end because love totally heals all.
I get the impression he's into her and doesn't like the other girl very much. Hence why he tries to subtly reject her and why he's so willing to jump at the opportunity to help his friend in need.