I...really don't understand what the fuck is up with this tone. First the pink haired gal is some kind of villain, scheming to snatch the male lead away. Now they're star crossed lovers. Wut.
it's heavily implied that MC is actually Hwi Yeon (the pink-haired girl) from the past, and Eun Wal's sister somehow either stole her body or changed her look to look like her and trick Eun Wal in the present.