@Ajuioke2 in the original novel this love interest isn't in love with her, but with her dead cousin (who is a few years older than them rather than a teacher adult). He chases (harasses) MC for many years trying to go out with her while never actually being in love with her. The one he stays faithful to forever is actually his dead childhood love, whom he made to promise to to look after MC. Also, MC doesn't die young this goes on for years (maybe even decades iirc?!).
They changed a bunch of stuff in this arc because the novel version was super messed up and no way fit for a drawn media, and presumably because the love interest was yet again a guy who couldn't take no for an answer even though he had "good intentions" this time. But yeah I agree although this guy was mildly jerkish in this its nowhere as bad as the novel version where he only ever showed his true emotions after she faked her death in front of him (with the building and cushion set up).