Butterfly Love Effect summary: Sul-Bi, a senior in high school, is struggling with being bullied at school and abused at home, as well as her lackluster life and attraction to other girls. She contemplates ending it all, but her plans change when she encounters a peculiar girl wandering the streets with no memory of her past. Sul-Bi is immediately drawn to this enigmatic girl, who goes by the name Gu Seju - a moniker Sul-Bi gives her to represent her as a "Savior." Despite having no recollection of her life, Seju possesses unique qualities, such as being impervious to hunger and pain. Every day, a cryptic note appears in Seju's pocket, acting as the only clue to her identity. Sul-Bi resolves to stay by Seju's side and solve the riddle of her past. But as they continue together, a stunning revelation is uncovered: Seju is actually Sul-Bi's future girlfriend who traveled back in time to meet her.