Gildeurineun Gongnyeonim

Istina was just an ordinary high school girl until she got struck by lightning. Upon opening her eyes, she realizes that she has woken up inside her favorite novel. At first, she's ecstatic that she'll get to meet her favorite character, Laon, but her excitement quickly dies down when she gets a look at her reflection in a mirror. The beautiful little girl looking back at her, with red hair and purple eyes, is the bully who torments Laon relentlessly and makes his childhood a living hell. But mending her relationship with Laon isn't the only thing Istina has to worry about. Laon is fated to die while protecting the female lead, but Istina isn't about to let that happen, even if it means that she'll have to get her hands dirty. Will Istina be able to tame the prickly swordmaster and change his ending at the same time?

(Source: Tappytoon)