Irene Lew

Irene Lew
Irene Lew, also spelled Irene Liu and Aileen, is the main female character in the trilogy, serving as Ryu's romantic interest, and the series' damsel in distress. She is an agent of the Secret Auxiliary Unit, working under the codename "Sea Swallow".

Irene's first encounter with Ryu is in Ninja Gaiden, where she shoots and captures him with a tranquilizer dart. She gives him the Shadow demon statue, and is later taken hostage by the Jaquio in order to force Ryu to hand over the statue. Although Ryu complies, the Jacquio keeps Irene to be sacrificed, and drops Ryu into a pit. However, Ryu manages to find a way out and defeats the Jacquio, escaping the collapsing temple with Irene. As the two fall in love, Irene disobeys an order from Foster to kill Ryu.

In Ninja Gaiden II: The Dark Sword of Chaos, Irene continues her role as damsel-in-distress. She is captured by Ashtar and held at the Tower of Lahja. She proves to be a distraction to Ryu, which Ashtar takes advantage of to ambush the ninja. Although Robert manages to save Ryu, Ashtar brings Irene away with him through the Maze of Darkness. When Ryu finally reaches her, it is for naught, as Ashtar maniacally stabs her from behind. Irene survives the blow, and tasks Ryu with destroying an altar. While she is being escorted out by Robert, they are ambushed by the Jacquio. Taken hostage yet again, Irene is sacrificed as a bait for the demons of the dark world when the Sword of Chaos awakens. Luckily, she is resurrected by the Dragon Sword's magic.

In Ninja Gaiden III: The Ancient Ship of Doom, Irene is attacked by Ryu's Doppelganger while investigating a secret lab. She falls off a cliff into the ocean and is presumed dead. Miraculously, she survives the fall, and turns up later during the last encounter with Foster. She points a gun at Foster to arrest him and stop his plan, but her weapon is useless against the Doppelganger. She is reunited with Ryu at the game's close after his journey through subspace to defeat Clancy.

Irene is mentioned by name in Ryu's backstory in the first Dead or Alive game, and appears in the Ninja Ryukenden.