However, unlike many people tend to believe, K' was a normal human being before the cloning operation. He led a normal life, but only for a few years after his birth. As an infant, K' was taken away by the NESTS agents, as the experiment subject for the prototype. He would be infused with Kusanagi power, and then the NESTS cartel would prove how feasible it was to inject the inmense Kusanagi power in a human being (obviously, the results were to be expected: normal human beings were unable to control the power, and thus, the neccesity of a special glove). The only thing K' reminds of his past life is a little girl that kept calling him "brother" and cried out for him. But this memory only exists in dreams now....

After activation, K' is sent out by his master, Krizalid, to join with his partner Maxima, and team up with Benimaru Nikaido and Shingo Yabuki in order to enter the King of Fighters tournament and collect battle data from the fighters of the competition in order to activate the Kyo Kusanagi clones around the world. Disgusted by such petty orders, K' joins Benimaru and Shingo with little, if at all, interest in the King of Fighters tournament. He didn't even talk with Maxima a lot, either. He was just a clone on a mission...and soon, many would fear the new beast of fire!

K' demonstrated his capacity as a fighter in the tournament, using interesting variations to the Kusanagi crimson flame power. Based on his sheer violent spirit, K' became a force to be reckoned with. Soon enough, he jumped to be the most sighted fighter of the tournament, not only by his cruelty and quickness, but by his totally different attitude and techniques from Kyo. K' doesn't mind any of it, and soon enough, he guides Benimaru and Shingo to the place of reunion set by Krizalid, in a sewer. The sewer drains to reveal a secret elevator that takes the whole team to the underground base of Krizalid. Somehow, K' sensed something exceptional would happen that day....

K' watches with little amusement as Krizalid does battle with Benimaru and Shingo. He knew that their attempts would be futile, but why did they keep trying? K' felt something exceptional in those persons...something he had failed to sense before: human compassion. He knew that the plot of Krizalid was to extract enough data from Benimaru and Shingo in order to activate the clones. So, as Benimaru was about to deliver a devastating blow, K' tried to stop him, to no avail. Krizalid had finished his process, and thanks K'. K' refuses to follow orders for Krizalid anymore, but Krizalid reminds him of his position as a clone. When in doubt, Krizalid asks K' about his parents or childhood...to which K' can not reply. However, one final data is amiss: the killer instinct. Krizalid asks K' if he desires it, but K' is not so sure anymore. However, before he can know it, Krizalid's final rampage is already in its fullest....

K' fights Krizalid alongside Maxima with unexpected feelings. He felt both excited and angry. He was tired of living under the shadow of Krizalid, and he would show him who manages the Kusanagi flames best! K' puts it all into his techniques, and manages to make Krizalid pass a hard time. However, it is not enough to defeat Krizalid. The end seems near, when all of a sudden, a crimosn flame blast puts Krizalid down. The assailant was no other than the original Kyo Kusanagi! K' finds in him the true challenge he was looking for, but before he has the chance to fight his original, a steel door slams in his face, closing both him and Maxima. A voice from above thunders in K's ears, asking him if he would prefer to live the life of a normal human. K' demands him to shut up, since he can do whatever he wants. The omnipotent voice of the NESTS cartel dooms both K' and Maxima to a swift death, as they are surrounded by the Ikari extermination squad that have already infiltrated the facility.

However, K' is not the one to be impressed by such toys. At the limit of his capabilities, K' unleashes the remaining force he has to blow several soldiers away, making his glove collapse. Now unable to stop his hand from flaming, he is aided by Maxima in escaping the collapsed base. There is still much to do for K', at the beginning of a new millenium...and a new life.

During a whole year, K' and his friend Maxima have been running away from two parties: first, the Ikari Warriors, who have been hunting them as fugitive criminals, and second, the NESTS cartel, who wishes to exact punishment for the traitors. K' has been on the run ever since, and managed to get away fighting from several precarious situations. K' thinks he should enter the next King of Fighters tournament, in the year 2000, in order to clean up his image, and eliminate his persecutors at the same time. However, he can't blow his cover by teaming up with Benimaru and Shingo again, so the situation gets even more complicated. It is then when K' is met by an enigmatic woman called Vanessa, who is accompanied by a jolly Mexican wrestler called Ramon. She offers to team up with them. K' doesn't trust Vanessa at all, but if you want to beat the lions, you might as well go in the den with them....

And so, K' gets another chance of proving his own worth, aside from the fact that he was just as Kyo clone. However, during the last few nights, K' has been having some weird nightmares: in each nightmare, a little girl shouts out for him in a lonely background. She claims to be her sister, but K' remembers nothing about her. What could all this mean? This further fuels K's rage to burn every poor commoner that cruised his way. This earns K' and his partners to once again return to Southtown for the final encounter. K' feels a lot of deja vu once he enters Southtown, and feels deeply connected to it. K' and his teammates walk through the docks in order to arrive at the factory zone, where they are supposed to fight their final match. It is then when K' senses a cold wind in the air...something that makes him feel full of fear. K' bids Maxima and the others to hurry on to the factory zone, and that he will stop the threat here. Maxima tries to talk K' out of it, but K' activates the flames in his hand. Maxima understands, and leads Vanessa and Ramon out.

K' shouts for the intruder to show himself. Oddly enough, an innocent young woman with long, blue hair, and a similiar outfit to K's, appears in front of K'. She claims to be the "anti-K'", and proceeds to attack K' with identical attacks to his own! K' has a hard time fending off the girl's ice attacks, as he tries to counter with his own fire attacks. Each attack counters the other, and the battle begins to wear out both of them. K' wonders who this girl really is, but by wandering off in his own thoughts, K' is blasted by a full-fledged ice blast from the girl. The memory of the young girl calling out for K' flashes in his mind again. Could this girl really be his sister? Desperate to know the truth, K' invokes a wave of fury, and creates an inmense raging fire aura around him. He gathers them to blast the young woman with a final flaming attack. K' drops to his knees, spent and exhausted.

To his surprise, the young woman is still standing! Burned badly, but with a kind smile on her face. The girl introduces herself as Kula, and she has been sent here to stop Zero, a NESTS agent that has become power-drunk, and intends to destroy his superiors with the help of the Zero Cannon. K' doesn't understand anything, but he gets animated when Kula tells him to go look for his sister, since she is looking for him. With new enthusiasm, K' rushes to aid his friends in the abandoned factory.

When K' arrives, he notices how Zero has already dealt with most of his partners, and even former partners. Zero notices K', and bluffs about how K' is in such a bad shape. K' realizes this will be a tough match, but is futher simplified by the fact Lin has poisoned him previously, and Maxima and the rest had already worn him out. With this in mind, K' calls upon the remaining ounces of strength, and fires Zero to oblivion. This unleashes the fury of Zero, who now intends to fry K' and the other fighters with the Zero Cannon. K' is dumbfounded, since he is too weak to attempt anything else. Nothing to worry about, though, as NESTS itself takes care of Zero via two female agents. With a bad feeling about all this, K' leads his friends to safety before the Zero Cannon destroys Southtown completely.

On their way out, K' finds out that Ramon and Vanessa were lost, but there was no time to stay around and think. Suddenly, a familiar figure appears in front of him. Is that the girl in his dreams? She seems older...but once she calls out K's name, there is no doubt: it is K's sister, and it turns out to be Whip, a member of the Ikari Warriors, K's persecutors! K', along with Maxima, escape from the devastated Southtown amidst a beautiful meteor shower. A beautiful show to eclipse the disaster. K's decides to willingly discard his protective glove. Maxima warns him, but by taking a glimpse at Whip, he promptly tears it off. To everyone's surprise, K's flaming power does not go out of control! He has finally learned how to control the legendary crimson flames of the Kusanagi. With a smile on his face, K' burns in anticipation of his final match with his former bosses...the NESTS.

Throughout his trips to several NESTS bases located around the world, accompanied by his sister Whip and by Maxima, K' finds something very suspicious in his findings: the bases they have tried to raid for such a long time are now deserted. Why is it that no one was there? K' suspects that someone is tracking their steps. During another ambush to yet another abandoned NESTS building, K' and the others stumble upon Lin, who has also been on the track of NESTS in search of the the traitor to his clan, Ron. Whip suggests taking him in to enter the next King of Fighters tournament, where NESTS will finally reveal themselves to the world. K' couldn't care less about Lin, but he was rather curious of what NESTS planned to do with trying to go public after destroying a whole city.

K', who still wears his special red glove out of sheer tradition (he no longer conceives himself without it), once again makes a smashing appearance in the King of Fighters tournament along the people whom he really cares about (except Lin). This is finally the chance K' has been waiting for all these years: the chance to exact revenge on NESTS. He didn't care who got in his way, everyone should fall! K's burning desire for victory allowed him to gather a strong spirit, and be able to classify to the finals, which would take place atop a blimp. K' noticed that something was terribly wrong the moment he boarded the blimp, and was proven right when a familiar figure appeared to challenge on the ship's bridge: the original Zero had came to defy them to a fight to the very end!

K' had to deal with Zero just as he did with his clone one year ago. While his friends dealt with Zero's companions, K' focused on trashing Zero. Even though the original Zero had a lot more power and skill than his clone, the techniques were almost the same, so K' took this as his cue to finish Zero once and for all. The defeated Zero accepts his defeat as a true warrior, and motions for the team to continue. The blimp, which had turned into a rocket ship of sorts, docked on a station in the heavens, and suddenly, the ship began to crumble. K' and the others hurry to board the station, not before giving a final glimpse at the man that he thought was a mere NESTS underdog, but was proud enough to let his enemies leave before they went down with him.

After boarding the station, K' notices that they have arrived at outer space! This should be the main HQ of NESTS, without doubt: a place which could not be discovered even if you scouted every inch of the world. K' knew he would meet his true destiny here, and he indeed encountered himself face to face with the president of NESTS himself in his own throne room! K' growled and cursed the leader of NESTS and his two companions, an attractive blonde secretary, and some tall man dressed in a cloak. The old man in the center seemed calm and didn't move at all, even under the pressure of K's insults. While K' was addressing the old man, the young man in the cloak grabbed the president by the head, and vaporized him! K' was surprised to realize that the lackey of the president (Igniz, the CEO of NESTS) was actually conspirating to overthrow the president and take his rightful place as the new god of the humans!

Igniz arrogantly tells K' about his plans and the project that involved the usage of the DNA of Kyo Kusanagi. Krizalid, Kula, and K' himself were the results of several experiments, and the final product turned out to be another clone called K9999, who was a completely artificial product of NESTS' technology. Then he confesses that he had to erase the memory data of K' so he could fight at his whole capacity, but since he thought it would be fun to watch a clone to actually have full awareness, granted K's memories back to him. With the memories of his childhood and his family now burning deep within his mind, K' stands poised to return the favor to Igniz and put an end to his twisted plot! But Igniz has already begun to set his plan in motion, as he summons all the inhuman power he had hiding deep within him (as a result of the fighting data that was collected the past few years), and challenges K' to do or die!

A cruel battle ensued, a fight which K' couldn't seem to win, terribly overpowered by Igniz and his incredible power. When all seemed lost, Kyo, Iori, and the other main heroes of the King of Fighters tournament arrived to get rid of Igniz and NESTS once and for all! With the help of the flames of Kyo and Iori, K' managed to channel a huge flame blast that overpowered Igniz himself and made the whole room tremble! A defeated and embittered Igniz slowly condemned all of his clones, and even tagged Whip as a useless clone herself! Amidst K's surprise, Igniz climbs a set of stairs to where two pillars were located. Since the humans would deny the existence of a god among them, they would have to be cursed with a demon instead! With those words, Igniz places his hands on the pillars, and sends the whole space station on a crash course towards Earth! As a huge door closes the passage to where the maniacal Igniz was, K' attempts to make a hasty retreat.

After escaping from the space station which crashed into the ocean, K' washed up on a nearby shore, exhausted and wounded. Still, he managed to go in Kula's rescue, who was trying to fight off K9999 and Angel, who were trying to finish her off, as ordered by Igniz. K' manages to drive a furious K9999 and Angel away, and promises that if K9999 ever messed with him again, he would know who was the true "beast of fire"!

Leaving Maxima, Whip, and the others to survey the ruins of the wrecked NESTS space station and the deceased Foxy, K' and Kula took a stroll down the beach. K' was trying to ask himself who was Whip, and if she really was her sister. He also wanted to know if NESTS was dead for sure, and what would K9999 do next? His eyes of sadness and confusion were hidden behind his trademark shades, but Kula could read right through them. Kula walks up to K', asking what would be in store for them now that NESTS is gone. K' just limits himself to respond that a new life would soon dawn on them, a life where they could make their own decisions, and be free from personal revenge from NESTS, as the morning sun begins to light on the young biological weapons.

K' is certainly bitter with life, being an unnatural creation and living underneath the shadow of Krizalid. He dislikes being ordered around, and wishes to live his own life as he pleases. His furious attacks in battle are to be feared indeed, since he seems to lose it. Antisocial and only friend to Maxima, K' is impervious to human feelings, and is a very cold and ruthless young man.