Why is this listed as a comedy/romance on IMDb? There are elements of both, but if I had to categorize this it'd be put squarely in the 'heavy drama' category.
In any case, the story is powerfully sincere and the lead actress Do-yeon Jeon (who won Best Actress at Cannes) is amazing. She's required to portray myriad changes in her character's world outlook and personality, and it is thanks to her that the central arc never feels choppy. Supporting actor Kang-ho Song is sweet but the way he plays his character leaves his encounters with other actors prone to a sort of emotional blocking. The film itself is earnest but a bit bloated, fat could have been trimmed (especially from the third act). Worth seeing.