Ninja Gaiden begins with a cinematic animation in which two ninjas duel to the death and one goes down. It is then revealed that the doomed ninja is the father of Ryu Hayabusa. When Ryu learns of this, he embarks on a quest to find out who killed his father and why.
This quest takes him to America to find an archaeologist with whom his father was working. From there, Ryu becomes embroiled in an evil, supernatural conspiracy involving a villain named Jaquio who has plans to use an ancient castle and some relics to unleash a terrifying evil upon the world.
Ryu will battle through urban city settings, forests, jungles, snow covered castles, underground railroads and ancient castles. A major feature in Ninja Gaiden are the cinematic scenes – sometimes fullscreen – through which the storyline unfolds.