The Yagyu Ninja Scrolls 1 : Revenge of the Hori Clan (Yagyu Ninja Scrolls)

After the Aizu Kato men imprison and humiliate the Hori men and their elite Seven Spears murder all but seven of the Hori wormen, the surviving Hori women vow to avenge their imprisoned and dead by murdering the Seven Spears in a most painful manner.