Since she was a child, Yeon-hee dreamt of becoming an action star. Even though she has an amazing swordsmanship, the reality of reaching her goal is just too hard for her to handle. One day, she is hired as a stand-in for an action film and goes onto the set, only to be transported to a lawless parallel world where people carry swords and kill each other without any retribution. Almost immediately, she is welcomed to the village as their protector and is respected by the villagers. And to save the villagers as a heroine, she begins to fight the villains back.

On May 9th, a female high school student was brutally murdered. There are 7 suspects and 7 shadows that terrorize them. Who are they and which one of them is you?