Satoko dreams of marrying a noble but can’t escape the assassin who has her within his sights.

Afflicted with a heart condition, Meiji-era noblewoman Satoko is determined to secure a marriage that will benefit her family before she dies. But before she can realize her goal, she’s targeted by a mysterious assassin named Shinpei. In a last-ditch effort to save her life, Satoko asks her would-be murderer to marry her. Her proposal isn’t sincere, but unfortunately for her, Shinpei loves as intensely as he kills. Can Satoko find a way to break the engagement without losing her life?

Imprisoned in the Okumura family dungeon, Shinpei, engulfed by jealousy, confronts a darkness within himself unlike anything he’s ever known. Meanwhile, marriage plans with Mitsuharu move forward against Satoko’s wishes. Finally the day of the wedding arrives, but as the light of celebration fills the air, Shinpei’s twisted love is unleashed!