Read the novel, fucking cried my tears out.
Spoilers regarding plot
As far as I remember, she was og Penelope. She has a power (there's more to it) and the only one who can stop Leila (acting Yvonne) from destroying their world. Vinter turns back time repeatedly to get to the path where Pene defeats Leila, but Pene doesn't know all about it (and that she has power or has to do something). Her personality has always been the same because of how people and her adoptive family treated her, so the future never changed. So every time her life repeats, she always suffered until her soul broke :( a piece of her soul reincarnated to her life in Korea, and it's brought back again to current story.
Literally thought this was gonna be a cute and fluffy story by the title…turns out it’s not. I expected the mc after going back in time, to be more wiser. Especially with that blonde hair guy, he’s two timing. Idk but…I guess he can’t run away.