Nabiingan

Na Bibi and her only friend Da-Hee, both bullied by their classmates, have been enduring a painful middle school life. But after turning 17, Na Bibi gained the ability to transform like a butterfly and be reborn infinitely with a different appearance.
With a brand-new pretty look, she is now ready to start afresh as a high school student. But her transformation stirs tensions with Da-Hee who disappears on her. Struggling with her identity, Na Bibi enters high school. She coincidentally ends up in the same class as Bang Yeonwoo, a student from the same middle school.
(Source: Manta)