Following his birth, Solid Wolf was given the name Sasuke. He spent his early life being raised by a variety of foster parents and never left the L1 Colony Cluster in his early years. Solid Wolf along with the other two clones of Heero , Liquid Wolf ( Itachi ) , and Solidus Wolf ( Eli ) were later recruited by STARWOLF.
A special forces unit in the G Team having been trained in , CQC ( Close Quarters Combat ) , high-altitude skydiving , linguistics , closed-circuit open-circuit combat diving , freerunning , and free climbing while in the special forces unit. During this time their true names and origins are classified by the Colony Liberation Organization never to be released to the public or to the three born from the project. Only Doctor J knows the true origins of the three people and the information was stored in his computer. Out of fear of retaliation or the collapse of the G Team and their special forces unit.


By this time OZ is making a play for the Colonies. By acting friendlier than the harsh Alliance, the organization won many supporters and succeeded in turning colonial sentiment against the Gundam pilots. Abandoning Wing on Earth in order to avoid enemy detection.
Heero proceeded to space to fight OZ there and attended school under Duo's name for his cover, as his code name would had only attracted more attention to himself. Learning that Duo had been captured, he broke into an OZ base to kill the youth, but instead decided to rescue him. Shortly thereafter, Heero learned that the Gundam engineers had been captured and were on the Lunar Base, building new machines for OZ. He went there to deal with them, but was captured by Trowa, who had entered OZ as a cadet to spy on them.

Recognizing Heero's skill, OZ set him to work piloting the new mobile suit Mercurius, with Trowa in the Vayeate to make sure he didn't try anything. A short while later, a new Gundam began destroying colonies seemingly at random. OZ dispatched Heero and Trowa to deal with it. They learned that the new suit was the Wing Gundam Zero, and it was piloted by Quatre. Distraught over his father's death and his mental stability affected by the ZERO System, Quatre had decided to destroy the colonies for their betrayal. During the battle, Trowa took an attack that would have killed Heero, destroying the Vayeate. Taking advantage of the distraction, Heero managed to capture Quatre, only for OZ to grab them both as well as Wing Zero. OZ had the boys test the ZERO System, but the effects made Heero rampage through their base until Quatre commandeered the Mercurius and managed to stop him. Escaping from OZ , The pair went back to earth.

When the two pilots arrived on Earth, they learned that OZ had put a bounty on their heads. Remaining with former Alliance members, Heero initially resisted Quatre's suggestions to go to the pacifist Sanc Kingdom. Instead, he left Quatre and signed up with a group of mercenaries fighting OZ, using his position as a Gundam pilot to gain their trust. However, OZ had just deployed the new Virgo mobile doll, and Heero, who was piloting an outclassed Leo, found himself facing death once more. He was saved by the intervention of both Quatre and Noin, the latter requesting them to come to the Sanc Kingdom. Finally relenting, Heero agreed, and headed to a reunion with Relena, the nation's sovereign. Though he remained in the Sanc Kingdom, Heero was averse to the nation's ideals, as he made plain to Relena on at least one occasion. Behind the young princess' back, Lucrezia Noin convinced Heero to protect the nation as part of an underground defense force, consisting of the Wing Gundam (which Noin had recovered) and several Taurus. After saving Relena's life from an OZ ambush, she agreed to allow the defense force, but tried to keep Heero from leaving by making him promise not to go searching for battles. Heero agreed and remained in the Sanc Kingdom for a while, using his Gundam to defend the nation.


Unknown to Heero that he had an ally that is also in the Sanc Kingdom at the time apparently sent there by Doctor J. Solid Wolf who appears similar to Heero but several years younger. The two then draw their guns and pointed it at each other when they meet.
Heero then asks the young teen his voice monotone and serious " who are you and why you look so close to me ? "
Solid Wolf then talks to Heero " Stand down , and you do not want to shoot me , my name is Solid Wolf and I know Doctor J , He told me to come here after his surrender to OZ forces.
L
ike you I am also a Gundam pilot the same thing goes for my two brothers who go by the codenames Liquid and Solidus Wolf they are also here in this nation as we speak... closer than you think. "
Heero then lowers his weapon a bit and out of the corner of his eye he sees two more males also around the same age and one of them is perhaps even younger like 10 - 12 years of age. Remembering the letter from Field Marshal Noventa's wife urging him not to be so careless with his life. Nothing can be done if you are dead.

Overtime Heero sees a lot of himself in the male dubbed as Solid Wolf and opens up to him viewing him as a brother though not knowing his origins or real name , or that of his twin and brother.

Some time later, however, Heero broke his word when he learned that Romefeller was sending Virgos to eliminate the Treize Faction in Luxembourg, where Treize was under house arrest. Upon arriving to assist the Treize Faction, Heero destroyed several Virgos, but his Gundam was eventually disabled. After receiving a message from Treize, Heero abandoned Wing for the last time and entered Treize's mansion. After their first face-to-face meeting, Treize gave Heero a new mobile suit, the Gundam Epyon, with which to determine his own path in life.
Unfortunately, Epyon's ZERO System proved too much for Heero to handle, often driving him to berserker frenzies. When OZ launched its final attack on the Sanc Kingdom, Heero continued fighting even after Relena surrendered and formally dissolved the nation. After that point, Heero encountered Zechs, who was piloting Wing Zero.

The two Gundams' ZERO Systems drove their pilots to battle , this catches the attention of Solid Wolf who arrives at the scene in a nick of time in his Transformable Assault Ground Mobile Suit , Gundam Rex , currently in its Mobile Armor mode.
Solid Wolf having a calm , clear and collected mind the ZERO System is under complete control to him acting as one and an extinction of himself. Solid Wolf then attempts to break up the fight firing a shot at the ground between the two Gundams using a High-energy Beam Rifle. Solid Wolf then calls out to Heero attempting to get him back to his senses " Snap out of it , its over , don't let the weapon control you "
He was successful at doing so when Epyon lowers its weapons. Wing Zero attacks again its pilot still being controlled by or under the influence of the ZERO system. Heero then calls Wolf's name and intercepts the attack. The pair then collapsed from the mental overload caused by their ZERO Systems. Having a brief conversation, the pair agreed to exchange Gundams, putting Wing Zero back in Heero's hands.