The setting is Sengoku era.
In the east island country constantly stricken with wars, multiple ninja clans maneuvering in the background exists.
One of them, the Suigen clan, started to weaken and its collapse is imminent. Leading that clan is the protagonist. Although his skill as a ninja is practically nothing, his management abilities and his capability to make enemy women betray their clan is top-notch.
With him at the helm, he plans to revive the clan and makes strenuous effort to subdue the wars.