I'm curious if the MC ever refers to the hero with actual gendered terms in the Japanese for the one shot, but it definitely seems like the author decided to retcon the whole not knowing thing. I do feel like it was stronger in the one shot than in the manga though? Idk I'm gonna read it as him either not seeing her as a love interest since she's so popular/already has lovers or just him being dense af since that seems to be what the author wants it to be read as.