Cast majority of rom-coms have girls fall in love with MC for no reason, even highly rated onces on Mangadex, Kubo-san wa Boku (Mobu) wo Yurusanai has almost a rating of 9, despite being utterly generic and the girl being completely in love with a non character of a MC for no goddamn reason.
@Kuroww
I don't think its so much that the female leads are assholes its that the male lead are so damn cowardly they get intimidated by flowers. You know the old saying "even a rat with bite back when cornered". The female lead in this story hasn't been an asshole, she has flirted and made somewhat sexual advances towards the main character. But this rat(mc) hasn't been cornered enough to bite back, so she must continue her flirting till mr. rat can take the bait.