A long time ago ------In the world of a battle nation, there were two countries competing for supremacy.
The Hakuonis who has the army like demons and trying to keep the world under control [Hakuoni Seibei].
The Haraguros who is exploiting girls to make his mistresses from his territory, and chanting "Tenka Fukan". [Haraguro Daizaemon]
Both are daimyos who are scared by people.

In such a war-torn world, there was a ninja group who was specialized in the dark work. .....It was called "Benisuzume".

"Benisuzume" is asked to assassinate Hakuoni Seibei secrecy by Haraguro Daizaemon.
The leader [Yuga] and his sister [Akane] sneak into the castle tower at Tenpei Castle at night to accomplish their mission.
Hakuoni Seibei had struggled with a sneak attack, but he died peaceful after getting Akane's Ninja assassination.
Thus, the battle between the two countries has closed the curtain secretly.

Now that the battle between the two countries is over, and the reunification of the world has been achieved by [Haraguro Daizaemon]
The era of battle has come to an end, and [Yuga] worries about Ninja would not need the existence of the world anymore.....

The devil's hand of [Haraguro Daizaemon] reaches to [Akane]