About Ninja Gaiden

Directly from the manual:

Ryu Hayabusa is a member of the Dragon Ninja clan, who have protected Japan for generations. He receives a message one day that the Dragon Village, home of the Dragon Clan, has been brutally massacred. He rushes home only to find that all but one of the village members have been killed.

The last survivor of the village tells Ryu with his dying breath that the sacred Bushido scroll has been stolen. The Bushido scroll is a scroll of power so strong that its owner can control the world.

The fate of the world is in Ryu's hands as he fiths against evil ninjas, gangsters and other villains to regain the Sacred Scroll of Bushido!

You are Ryu Hayabusa, last of the Ninja of the Dragon clan. You must fight your way through eight levels of villains to retrieve the Bushido. Each level gets progressively harder, and your skills will be tested to the limit. But don't give up. The fate of the world rests squarely upon your shoulders!