 The story begins one year after the events of the first Ninja Gaiden game. The story opens in the Realm of Darkness as Ashtar, the evil lord who controlled Jaquio, is informed of Jaquio's defeat; he devises a plan to rule over Earth by opening the Gate of Darkness. A U.S. Army Special Intelligence unit member named Robert T. Sturgeon is sent to find Ryu to take out Ashtar. Robert informs Ryu that Irene Lew has been captured and that he must go to the Tower of Lahja to save her. After hopping on a freight train and then battling up the mountain in which the tower lies, he is ambushed by a figure who describes himself as a tribesman of the World of Chaos, led by the Emperor of Darkness Ashtar. After making it to the top of the tower, Ryu finds Irene, who has been captured by Ashtar. Ashtar then blasts Ryu with energy from his own sword; before Ashtar can finish off Ryu, Robert appears and shoots Ashtar in the back, stopping him. Robert orders Ashtar to hand over his sword and give up, but Ashtar escapes with Irene, telling Ryu to follow him into the Maze of Darkness.
