It's Goo Ra Ra's big day. Sun Woo Joon catches her off-guard with a memorable first encounter, moments before her world comes crashing down.

Eun Dan Oh is a 17-year-old high-school student from a wealthy family who suffers from a lifelong heart condition that inevitably means she will not live past her teenage years. However, when Dan Oh realizes she is experiencing long gaps in her memory as well, she comes into the unhappy inheritance of another fact in her life: she is a character in a Korean webtoon and all of her actions are predetermined by the artist who draws her.