A beautiful mess, completely constructed around plot holes. What happens when teen romance comic book supporting characters become self-aware? It's an emotional rollercoaster, like real-life adolescence is, itself, as well as a comment on the nature of reality.
The music is a character, poignantly reminding us that adolescence is not about superficiality, even as the kids get up to a fair amount of stereotypical high school goofiness.
The embedded comments on the nature of reality sneak up in the form of kaleidoscopic changes to the main character's (an extra in the comic book who rebels against her fate) school uniform that don't seem to show up on anyone else. (I'll have to watch again).
The explicit theme of an unseen cosmic force negating free will and the defiance of individuals against it is the one consistent character-driven plot thread.
it throws almost every Kdrama cliché into the story:
Amnesia, half-sibling rivalry, life-threatening illness, not one but two love triangles, school bullying, marriages of convenience, class conflict, plus a big dose of time travel. THIS IS NOT NECESSARILY A BAD THING, especially since all of these tropes are dealt with self-referentially.
It sure takes its time making its point that there may be no point, but least it does so beautifully.