The time is Meiji.
Satoko, a noblewoman with little time left to live, is kidnapped and imprisoned in the "Yuyodo".
In order to get the hitman Shinpei on her side, she enters into a fake engagement, but she finds herself in a situation where she cannot escape because she is strangely in love with Shinpei...
Two people plan to escape by disguising themselves as girls.
But Shinpei can't forgive another man for touching Satoko?!

“I’m the one who will protect Satoko.”

The more Satoko becomes attracted to Shinpei, the more guilt she feels about the fake engagement grows.
Shinpei notices something strange about Satoko――? The two people who had no intention of getting along begin to get closer.