Raiden is the codename of the rookie operative recruited by FoxHound to liberate Big Shell from the terrorist organization Dead Cell. While never experiencing actual combat, he is a veteran of over 300 VR missions, including simulations of the Outer Heaven, Zanzibar, and Shadow Moses campaigns. His superiors at Foxhound, including Colonel Roy Campbell, feel he has the potential to become the next Solid Snake. Which is ironic since Raiden shares similarities to Grey Fox.
Raiden is outfitted in a state-of-the-art stealth outfit known as a "Skull Suit," which is equipped with electro fiber technology and a large array of sensors known as "Smart Skin" that can detect injuries and communicate with the nanomachines in his body to create a feedback system. Raiden's intravenous nanomachines also serve to provide communications with Foxhound and access links to security nodes inside Big Shell.
Raiden has no known family and his only close acquaintance is his girlfriend Rose, who acts as his mission analyst for the Big Shell operation. Eventually he found out that Rose gave birth to his son named John who's nickname is 'Little Jack'.
Before being recruited by FoxHound, Raiden was in the U.S. military as part of the Army's Force XXI trials. His past before joining the service is unknown, even to him, as he suffers from an unrecognized form of Dissociative Amnesia.
During Liquid's Insurrection, Raiden was outfitted with a highly advanced cyborg suit which gave him a higher degree of strength, speed and agility. He eventually fought Vamp in Shadow Moses while Snake was keeping the Gekko at bay. However, before these events happened Raiden saved Olga's daughter Sunny from the Patriots gave her to Otacon and Solid Snake to look after her.
During the events of Big Shell, Solidus Snake recounts the events of Raiden's past. Raiden was orphaned during the Liberian Civil War in the late eighties, and Solidus was quick to adopt the child. By 1990, at only the age of ten, Raiden was a merciless child soldier, adept in the art of war and genocide.
Raiden remembers none of this because he undergoes extensive treatment, such as drugs, brainwashing, and synaptic nano-manipulation to suppress these memories when he is taken in by The Patriots.
Metal Gear Solid 2: Sons of Liberty
In Metal Gear Solid 2: Sons of Liberty the player takes control of Raiden in the Plant chapter; he is introduced as a newly recruited, virtual reality-trained member of FOXHOUND with no live combat experience before his current mission. Assisted via Codec by his commanding officer, the Colonel, and his girlfriend Rosemary, Raiden's initial objective is to rescue several hostages from a terrorist group known as the Sons of Liberty. Raiden is helped by the mercenary Solid Snake and the spy Olga Gurlukovich across his mission. As the story progresses, Raiden is revealed as a former child soldier for the Sons of Liberty's leader, Solidus Snake, during the Liberian Civil War. After the war's end, Raiden was given a normal life and tried to forget his past. An organization known as The Patriots is revealed to be controlling his actions, however, with his commanding officer revealed as their computer-generated AI. One of their spies, Rosemary, becomes Raiden's girlfriend, and the two fall in love for real. Raiden defeats the Patriots' enemy, Solidus, after being told by their AIs that his death would also trigger the deaths of Olga's child and Rosemary, the latter of whom was revealed to have been pregnant with Raiden's child during the mission.He later reunites with Rosemary, and both decide to stay together to raise their unborn child.
Metal Gear Solid 4: Guns of the Patriots
In Metal Gear Solid 4: Guns of the Patriots, set five years after Metal Gear Solid 2, Raiden is said to have disappeared after rescuing Sunny, the daughter of the late Olga Gurlukovich, from the Patriots, and is searching for the corpse of Big Boss for Big Mama. The trauma of his breakup with Rosemary, coupled with the apparent miscarriage of his child, have made Raiden believe his only place is on the battlefield. Outfitted with a cybernetic exoskeleton as a result of The Patriots' machinations, Raiden joins Snake's group in their fight against Revolver Ocelot who wants to obtain the Patriots' powers. After several encounters with Ocelot's men, a wounded Raiden stays in the ship Outer Haven to protect Snake as he shuts down the Patriots' AIs. In an epilogue, Rosemary reveals to Raiden that their child was not miscarried; her marriage to Roy Campbell was a hoax to protect her and their son from the Patriots. Upon hearing this news, Raiden reconciles with Rosemary.
Metal Gear Rising: Revengeance
Raiden appeared as the main character in Metal Gear Rising: Revengeance. Four years after Guns of the Patriots Raiden joins the private military company (PMC) Maverick Security, in multiple tasks while raising money for his family. However, they are attacked by a group of terrorists called Desperado Enforcement LLC that kill his protectee and leave Raiden near dead. Saved by Doktor, Raiden gets a improved cyborg upgrade and starts working with Maverick to fight Desperado. His already vengeful obsession with Desperado becomes even more personal when he discovered, during a mission into Mexico, that Desperado and World Marshal Inc had been kidnapping several children, surgically removing their brains to place them in cybernetic bodies, and were planning to subject them to VR similar to his own. This results in Raiden abruptly resigning from Maverick to pursue and retrieve the children's brain casings from World Marshal, having to battle his "Jack the Ripper" persona in the process. Although Raiden is successful in defeating Desperado, he learns that Steven Armstrong was using such PMC to distract Raiden as he attempts to start a terrorist event that would result in a global war. Raiden manages to stop Armstrong's actions and decides not to return to Maverick, instead he begins to fight "in his own war".