The time is Meiji.
Born without any lack of family or beauty,
I hear that I don't have much time left to live.
The dream of Countess Kirigaya Satoko
Just getting married for the benefit of the family.
One day, a mysterious assassin suddenly targets him.
Satoko is trying to save her life right now.
He proposes to the hitman Shinpei Goto.

“Please marry me.
“If you marry me, you can have everything.”

It was only a lie at that time, but Shinpei was a man who was incredibly heavy on love… .
I can't escape from this engagement──?!