During a turbulent time, political upheaval, rebellion, and invasion come to a head in a clash between two swordsmen caught up in a violent and bloody struggle to seize control of the country they love. With their allied army standing behind them, they will meet for the most important battle of their lives. Swords will be drawn while many lives are lost, and only one swordsman will walk away the new king of the land.

Strange rumors start to spread at the catholic girls' high school after Unjoo commits suicide one night. Unjoo's younger sister Jung-un, who attends the same school, gets suspicious about Unjoo's death. After persistent investigation, Jung-un finds out that on the night of the incident, Soy, Eugene, Eun-young, and Unjoo tried to commit a joint suicide after making a vow on blood. But the other three are still alive...