"Get back in one piece, people! Please."
—Irene in Dead or Alive Dimensions

Irene Lew, otherwise known as Aileen in the first Dead or Alive, and by the codename Sea Swallow, is a CIA agent and an ally of Ryu Hayabusa from the Ninja Gaiden series.

She is the main female lead in the original Ninja Gaiden trilogy for the NES, serving as Hayabusa's romantic interest and the series' damsel in distress. In the reimagining of the original NES series of Ninja Gaiden, Irene was first introduced in the 2008 title Ninja Gaiden II using the name "Sonia", before using her real name in Dead or Alive Dimensions, which marked her first visual appearence in the Dead or Alive series.


The Second TournamentEdit

Assigned by the CIA to investigate the Dead or Alive Tournament Executive Committee, Irene encountered her partner Hayabusa after he departed from Lisa Hamilton's suite on the Freedom Survivor, with information on DOATEC Germany. After Hayabusa retrieved data and Kasumi from the research facility, Irene analyzed it and both are shocked to discover that DOATEC has resurrected Hayate from his comatose state.

Kasumi wanted to go find her brother, but Hayabusa stood against the idea and slapped Kasumi. Irene rebuked Hayabusa for hitting her, but when Kasumi left anyway, she was unable to stop Hayabusa from sending Ayane after her. While Hayabusa was knocking other fighters out of the competition, Irene infiltrated DOATEC and investigated further. After the tournament, she finally meets Hayate, fully recovered from his amnesiac state.

The Third TournamentEdit

While investigating the tournament sponsers in DOATEC, Irene watched the fight between Hayabusa and Hayate with Ayane. She tried to talk Ayane into stopping the two men from having to use their Ninpo techniques on each other, but she was captured by the assassin Christie and was used as bait to lure Hayabusa away from the Tenjin Ninjas for Genra to get his hands on them. Hayabusa rescued Irene, but they were almost too late to stop Genra, prompting the Super Ninja to save them.

The Fourth TournamentEdit

Backing the Mugen Tenshin Clan on their assault against DOATEC, Irene and the CIA assisted in the raid on DOATEC's facilities. She stated that the codename for the operation is "Sonia", and asked that the shinobi come back alive.



Irene's appearence seems to have changed in Dead or Alive: Dimensions from Ninja Gaiden, to match the "anime-style" of Dead or Alive. Her eyes are now blue and larger in size, her face is rounder, her lips are now pink, and her hair is slightly longer and more layered. She also wears a more casual outfit, as apposed to the spy-styled dress in Ninja Gaiden, composing of a hot pink corset-like shirt, a green army jacket, ripped black tights, and tanned boots and mini-shirt. She is still pale-skinned, platinum blonde, and still sports her red tattoo, a belt with magazine holders, and cord necklaces, although the cores are now much shorter.


Irene is a gutsy woman who is also gifted with a knack for espionage. She is highly skilled with firearms of many different kinds, from hand guns to RPGs. She is also very loving and affectionate to Ryu Hayabusa as well when he is around her. She is quite firm and serious when it comes to her jobs especially dealing with Ayane about Ryu's whereabouts as seen in NInja Gaiden.  


Irene is from the name Greek Ειρηνη (Eirene), which derived from a word meaning "peace". This was the name of the Greek goddess who personified peace, and was one of the Horae.

The alias, Sonia is used in the many areas of the world including the West, Russia and India. In Hindi, the name means 'golden', derived from सोना (sonā) which means 'gold', which in turn comes from Sanskrit सुवर्ण (suvarṇa; su- means 'good' and varṇa means 'color'). Her codename "Sea Swallow" is another name of the Common Tern, a seabird.


Ryu HayabusaEdit

Her relationship with Hayabusa began in the original NES version of the series. As a CIA agent she was under orders to retrieve the twin Demon Statues, and afterwards fell in love with Hayabusa, ultimately running a curio shop together. In the rebooted version of the series, Irene and Hayabusa meet during the Demon Statue Incident in Ninja Gaiden II, where the two of them started off as professional partners. As things progressed, Irene slowly developed feelings for him, as evidenced from when he defeated the Demon God Vazdah the first time around and ran up to hug him.

In Dead or Alive Dimensions, Hayate and Ayane can see something going on between the two, but Hayabusa and Irene seem to keep them guessing on what their relationship entails.


Dead or Alive seriesEdit

  • Dead or Alive Dimensions (non-playable, 2011)

Non-Dead or Alive appearancesEdit

Ninja Gaiden NES TrilogyEdit

In the original Ninja Gaiden trilogy, Irene is an agent of a Secret Auxiliary Unit, working under the codename "Sea Swallow". However, she is shown to have quit that job and instead began working as a CIA analyst during the events of Ninja Gaiden III: The Ancient Ship of Doom.

At some point in the series, she marries Hayabusa and helps him run an antique shop in America. However, following the re-boot, they are not married but do appear to be in a romantic relationship.

Ninja Ryūkenden OVAEdit

Voiced by Yumi Tōma, Irene appears in the Ninja Ryūkenden OVA where she is once again kidnapped, forcing Hayabusa to take up his sword to protect her.


Promotional renders
Promotional images
Ninja Gaiden series


  • Irene is mentioned in the first Dead or Alive, but only through Hayabusa's biography.

External linksEdit

Navigation boxesEdit

v · e · d
Main series Dead or Alive - Dead or Alive 2 - Dead or Alive 3 - Dead or Alive 4 - Dead or Alive 5 - Dead or Alive 6
Spin-offs and related titles Dead or Alive++ - DOA2: Hardcore - Dead or Alive Ultimate - Dead or Alive Online - Girls of DOA BlackJack - Dead or Alive Dimensions - Dead or Alive 5+ - Dead or Alive 5 Ultimate - Dead or Alive 5 Last Round
Dead or Alive Xtreme sub‑series Dead or Alive Xtreme Beach Volleyball - Dead or Alive Xtreme 2 - Dead or Alive Paradise - Dead or Alive Xtreme 3
Canceled games Dead or Alive: Code Chronos - Project Progressive
Related series Ninja Gaiden series - Virtua Fighter series - Warriors series
Playable characters Main cast Kasumi - Zack - Ryu Hayabusa - Bayman - Leifang - Gen Fu - Tina Armstrong - Jann Lee - Bass Armstrong/Mr. Strong - Ayane - Helena Douglas - Leon - Ein - Hayate - Hitomi - Brad Wong - Christie - La Mariposa/Lisa Hamilton - Kokoro - Eliot - Rig - Mila - Momiji - Rachel - Marie Rose - Phase 4 - Nyotengu - Honoka - Diego - NiCO
Secondary Kasumi α - Shiden - False Kasumi
Final bosses Raidou - Bankotsubo - Genra - Alpha-152
Xtreme only Misaki - Luna - Tamaki
Guest characters SPARTAN-458 - Rio - Akira Yuki - Sarah Bryant - Pai Chan - Jacky Bryant - Naotora Ii - Mai Shiranui
Non-playable characters Main series Alicia Armstrong - Anastasia - Anne - Ayame - Burai - Chen - Fame Douglas - Goldie - Hitomi's father - Irene Lew - Isabella - Kuramasan Maouson - Lauren - Maria - Mei Lin - Miyako - Muramasa - Niki - Victor Donovan
Guest characters Ridley - Samus Aran
Non-canon characters Max Marsh - Weatherby
Miscellaneous characters Toreko
Gameplay modes Story - Versus - Arcade - Time Attack - Survival - Tag Battle - Team Battle - Training - Online - Spectator - Album - Movies - Fight Record - Titles - Help & Options - Music
Gameplay terms Attacks - Boss Battles - Character Select - Cliffhanger - Combo - Counter Blow - Critical Hit - Danger Zone - Game Over - Holds - Knocked Out - Match - Move Data - Power Blow - Power Launcher - Replay - Side Stepping - Special Moves - Stages - Stances - Tag Throws - Attack Change - Triangle System
Plot subjects DOATEC - Dead or Alive World Combat Championship - Mugen Tenshin clan - Ninpo - Nukenin (missing shinobi) - Project Alpha - Project Epsilon - Shinobi - Tengu
Other terms Credits - Cutscenes - Endings - Glasses - Openings - System Voice - Tournament Winners
More information and archives
Actors - Canon timeline - Command Lists - Costumes - Fandom - Gameplay - Items - Locations - Martial arts - Media - Merchandise - Movies - Music - Soundtracks - Staff - Tag Throws
v · e · d
Playable Kasumi - Ayane - Hayate - Ein - Ryu Hayabusa - Helena Douglas - Christie - La Mariposa - Hitomi - Bayman - Kokoro - Jann Lee - Leifang - Tina Armstrong - Bass Armstrong - Zack - Eliot - Gen Fu - Brad Wong - Leon - Raidou - Genra - Alpha-152 - Kasumi α - Tengu
Secret character Shiden
Non-playable characters Anne - Ayame - Fame Douglas - Irene Lew - Lauren - Maria - Victor Donovan
Guest characters Ridley - Samus Aran
Gameplay modes Chronicle - Arcade - Survival - Tag Challenge - Free Play - Training - Local Play - Internet Play - Showcase - 3D Photo Album - Fight Record - Options
Gameplay terms Attacks - Boss Battles - Character Select - Combo - Counter Blow - Critical Hit - Danger Zone - Holds - Knocked Out - Match - Move Data - Side Stepping - Special Moves - Stages - Stances - Tag Throws - Throws - Triangle System
Plot subjects Dead or Alive World Combat Championship - DOATEC - Exiled shinobi - Mugen Tenshin Ninja Clan - Ninpo - Project Alpha - Project Epsilon - Project Omega - Runaway shinobi - Shinobi - Torn Sky Blast
Martial arts Ba ji quan - Combat Sambo - Drunken fist - Jeet Kune DoKarate - Lucha libre - Muay Thai - Ninjutsu - Pi gua quan - Pro-wrestling - Snake fist - Tai ji quan - Tengu-do - Xing yi quan - Xinyi liuhe quan
Other terms Credits - Cutscenes - Endings - Figurines - Genra (wine) - System Voice - Tournament Winners
Stages 999 Meters - Azuchi - Danger Zone - Dojo - Eternal Helix - Fallen Miyama - Freedom Survivor - Frozen Peaks - Genetic Biolab (Advanced) - Geothermal Power Plant - Hellfire - Kyoto in Bloom - Lorelei - Sacred Miyama - Tao - Whitewater Valley
Non-playable locations Great Opera - Mugen Tenshin Village
Character themes "Alpha-152" - "Ayane's theme" - "Bass' theme" - "Blood Tie" - "Cracker" - "DEAD OR ALIVE" - "Gen Fu's theme" - "Hayabusa's theme" - "Jann Lee's theme" - "Jintsuriki" - "Karma" - "Kasumi's theme" - "Kasumi α's theme" - "Knifepoint" - "Leifang's theme" - "Monster" - "Moonlit Lady" - "Red Moon" - "Reincarnate" - "Shiden's theme" - "Successor" - "Tina's theme" - "Tribal Beats" - "Turn On The Lights" - "Vigaku" - "Zack's theme"
Chronicle Mode tracks "Brave Heart" - "The Broken Arrows" - "Dance Of The Angel" - "DOATEC" - "Ketsui no Toki" - "Look Ahead" - "Tengu-mai" - "Unbroken Chains"
Other tracks "D.O.A. (Dimensions)" - "Dimensions Training" - "Vs. Ridley" - "Wired"
Command lists - Costumes - Downloadable content - Fighting quotes - Merchandise - Promotional artwork and wallpaper - Tag throws