Having dealt with the Koga ninja, Shintaro faces new foes, the Iga ninja, a group of highly trained and very dangerous assassins led by the somewhat fanatical Momochi Genkuro.

Momochi and his group were hired by the Lord of Owari to assassinate Matsudaira Sadanobu.

However, Momochi saw this more as an opportunity to create the necessary chaos, to topple the shogunate and plunge the country back into civil war and to start a golden age of ninjitsu.

It was Shintaros task, aided by his loyal side-kick Tonbei, to save Japan from an era of blood and murder.