Yashamaru was selected by Ogen to fight for the Iga in a peerless demonstration at Sunpu Castle. Using his bizarre ability to exert long cutting strands of women's hair upon his enemy, at his bidding, Yashamaru controls whether they will slice enemies in half or momentarily tie them in a bind. They can even cut through stone! Gathering black strands of women's hair and coating them with a secret animal oil, Yashamaru yields his secret weapon called Gokujou. Also he's happily engaged to Hotarubi

(Source: FUNimation's Official Basilisk Website)