Manwha/manga/manhua with romance as the main theme. No reincarnation, no isekai, no magic/another world; there's another list for them. If there are comics that don't fit in the genres mentioned before, I will put them in this list even if the romance theme is not prevalent.
I will also list stories that may start as reincarnation/isekai but later will have no effect on the story.
