when the protagonist said "affectionate and liked Yeoni, there wasn't much else about him except that he lived by himself next door" about Hana, it caught my attention. it seems she was talking about "original Hana" (a second lead love interest who doesn't get that much attention and isn't given enough development). now that she's been actively pursuing Hana, I think she's making the manhwa (the manhwa that she was transported to) change. she's starting to navigate a new version of the manhwa, created as a result of her own actions. a version in which Hana is more relevant so he inevitably has more lore
@effel so I think that's why there are things about Hana that the protagonist doesn't know about. it's probably lore that didn't even exist originally (the character "Yeoni" would know though - remembering that our protagonist is someone who replaces the original Yeoni)