Hayate is a shinobi and the eighteenth master of the Mugen Tenshin Ninja Clan. He is eldest child and only son of Shiden and Ayame, making him Kasumi's older brother, and Ayane's older half-brother. He is also friends and allies with Ryu Hayabusa.
Although he was first mentioned in the first Dead or Alive in 1996, Hayate's official debut appearance was in the 1999 title Dead or Alive 2 as Ein; a amnesiac Karate master. He regained his memory during the second game and finally appeared as himself in 2001 for Dead or Alive 3.
In Dead or AliveEdit
Hayate is the eldest child and only son of Shiden, the now-former leader of the Mugen Tenshin Clan, and Ayame. He was born to be the next leader of the clan, to follow on from his father. He seemed to have a happy childhood, training in the art of the clan, Tenjin Mon-styled ninjutsu, with his younger sister Kasumi, who loved him dearly.
After Genra requested to Shiden for Ayane - the village's "cursed child" and his foster daughter - to begin her training, Hayate started to form a friendship with the girl, treating her with kindness, which most of the clan didn't give her.
The two formed a strong bond, but soon after, Ayame admitted to Ayane that she was her daughter, meaning that she was a half-sister to Hayate and Kasumi. Despite this life-changing revelation, and the falling-out between Ayane and Kasumi, Hayate reminded to have strong relationships with both of his sisters over the years.
During his early life, Hayate also became good friends with Ryu Hayabusa, who like him was next in line to be the master of his own clan, the Hayabusa Clan.
Raidou's Attack and the AftermathEdit
When Hayate was 23, Raidou, Shiden's traitorous brother who was banished from the clan, returned to their village and attacked the clan in an attempt to "steal" the Torn Sky Blast ninpō attack.
Hayate and Ayane were at the front line to defend the village. Ayane attacked Raidou to defend her brother, but was quickly defeated. Hayate ran to her aid, but when Raidou called him a "weakling" for hiding behind a woman, Hayate attacked him in rage. He used the Torn Sky Blast to fight Raidou, despite Ayane's protests, but he was overcome by his uncle's superior fighting skill, and the Torn Sky Blast was stolen from him. As both of their ninpō attacks collided, the resulting explosion threw Hayate into a tree, cracking his spine and sending him into a coma.
Despite Kasumi dutifully looking after him, Hayate's remained in his coma and seemed doomed to stay in that state, with some of the shinobi considering him to be "dead". Because of this, his entitlement to the title of clan master was past down to Kasumi. Soon after Kasumi learned the truth about the cause of Hayate's coma from Ayane, she fled the village to seek revenge against Raidou for Hayate during the first Dead or Alive World Combat Championship, despite the fact that leaving the village without permission branded her as a runaway shinobi.
Project Epsilon and the Second TournamentEdit
Shortly after the events of the first tournament, Hayate - still in his coma - was kidnapped by Kasumi Alpha, a clone of Kasumi, for the Dead or Alive Tournament Executive Committee and was taken to DOATEC Germany, one of their research labs located near the Black Forest.
While in their possession, Hayate was made to undergo various experiments as part of Project Epsilon, which was headed by Lisa Hamilton. DOATEC planned to create the perfect super-human weapon by reconstructing Hayate, just as they were using Kasumi's DNA around the time for the same purpose. Using the experiments to enhance his body's nervous system, they managed to repair his spine but did little else to him at the time.
Shortly before the second tournament began, Ryu attacked DOATEC Germany to save Kasumi (who was also being held in the same building) and caused the building to set alight. The DOATEC staff, along with Hayate, were taken onto helicopters to escape the blaze and continue their experiments at another building, but the helicopter Hayate was in had engine failure and crash-landed in the Black Forest.
Hayate got away from DOATEC and the crash alive and was lucky enough to run into Hitomi, a Karate student who was training in the forest, before collapsing. Due to the traumatic events he went through, Hayate began to suffer from amnesia, and he could not remember his past or even his name. He was taken in by Hitomi's family, and ended up going by the name of "Ein".
Hitomi's father, a master of a dojo, trained Ein in the art of Karate. Ein quickly picked up the style and was made an instructor in the dojo, but he soon left to join the second Dead or Alive Tournament, to find answers to his lost past. During the early rounds, Ein encountered Ryu. He was defeated by the super ninja, which caused Ein to regain some memories about him.
Sometime after the tournament, he encountered Kasumi, whom he still didn't remember. Ryu encouraged them to fight each other, saying that when the blood of two siblings meet in battle, the very soul of a shinobi will awaken. Sure enough, after he defeated Kasumi and knocked her unconscious, Hayate's memories returned.
Shortly afterwards, Genra appeared before them and revealed himself to be the one who broke the barrier that separates the Spirit World from Earth, allowing Gohyakumine Bankotsubo to enter the human world and cause chaos. As the traitorous ninja made his leave Hayate and Ryu confronted Ayane, who was under Genra's control, and Kasumi Alpha, Kasumi's clone. Together with Ryu, they were victorious.
After the fight, Ryu introduced Hayate to his friend, CIA agent Irene Lew who tells the men that the CIA have been watching DOATEC and their shady actions for some time. After Ayane regained consciousness, they soon realized that Kasumi disappeared, leaving Hayate in a highly worried state.
The Third TournamentEdit
After Genra turned against the clan, Hayate requested his father to allow him to hunt down the traitor, which made Shiden believe that Hayate may be ready to take over as the leader of the clan. Hayate wanted to find Kasumi first, but Ayane spoke against it, calling Kasumi a traitor and suggesting that she might had been consorting with Genra. Enraged by her words, Hayate slapped Ayane. Shiden rebuked the two for quaralling, and dismissed Ayane, while asking Hayate to train with him, although Hayate didn't understand why.
On a moonlit night at the Azuchi, Ryu tells Hayate that he was no match for the Jonin who once headed the Hajinmon. Hayate retorts that Ryu knew nothing about Genra, and challenged him to prove he could beat someone if he had to. He defeated Ryu, only to discover it was a fake copy Ryu had created using the substitution technique. Bewildered at first, Hayabusa told Hayate that they'd meet again in the upcoming third DOA tournament.
Getting a lead on Kasumi's whearabouts in Kyoto, Hayate and Ayane join the third tournament. While on the Freedom Survivor, Hayate met up Hitomi again for the first time since he left her family's home when he was Ein. Hayate introduced Ayane to Hitomi, who assumed that Ayane was Kasumi, the girl who Hayate was mumbling about when they first met. Angered for being mistaken for Kasumi, Ayane fought Hitomi. After the fight, Hayate revealed to Hitomi the truth about his shinobi identity, much to her surprise.
The siblings also crossed paths with the legendary Gen Fu, and his student Eliot. Hayate paid respect to Gen Fu's skills and reputation, before they engaged in a tag-team fight. Although Ayane became annoyed with Eliot and his lack of self-confidence, Gen Fu admired her fiery spirit and Eliot thanked her greatly for the fight, which caused Ayane to walk off, leaving Hayate trying to keep up with her.
Some time later, Ayane and Hayate argued about who should take down Genra; Hayate felt that as leader of the clan, it was his duty to take down the former master, but Ayane too felt it was her task, being Genra's foster daughter and heir. After fighting about it, they both agree to work together to take down Genra.
During the rounds of the tournament, Hayate met with Helena Douglas, who recognized him as the subject of Project Epsilon. Hayate demanded to tell her why Genra joined DOATEC, but she claimed she didn't know, that Genra and even herself were just puppets that DOATEC controled. After defeating Helena in battle, he told her that he would defeat Genra, and she should leave DOATEC for her own safety.
A while later, Hayate and Ayane met up with Ryu and Irene, and the men engaged in battle to see who was the greater shinobi. The fight became extreme as the boys started a ninpo duel, but were stopped by Ayane as Irene was kidnapped by Christie. Ryu ran off to save Irene, but Hayate and Ayane realized that her kidnapping was just a distraction for Genra. The fallen master created a portal to Hellfire, and transformed into his powerful Omega form.
The two shinobi try to take him down, but Genra proved too strong and they were starting to become overpowered by him. When Ryu realized that Christie was just a decoy, he quickly ran to aid his friends, and ran Genra through with the Dragon Sword. Before the monster could regenerate, Ayane and Hayate performed a duel-spell together and struck the final blow, killing Genra.
The Fourth Tournament and The Fall of DOATECEdit
Angered for his clan being used as guinea pigs for DOATEC's inhuman experiments, Hayate resolved to take them down with help from the CIA. As the fourth tournament approached, the Mugen Tenshin Clan set out to defeat DOATEC once and for all. Before they left for the DOATEC Tritower, Hayate encountered Kasumi, who tried to convince him to simply return to the village and prevent all-out war against DOATEC. Still filled with shame and grief over Kasumi being a renegade, Hayate didn't speak a word to her. However, Ayane intervened and stopped her sister, asking Hayate to go ahead without her. He left Ayane and Kasumi to battle.
Hayate commanded his men to attack the Tritower, and with the assistance of Irene, he entered the building with Ayane and Ryu, fighting through DOATEC's private army. Part-way through the attack, he encountered Lisa (in her wrestling persona La Mariposa), who hinted that she had something to do with his vendetta against DOATEC. Hayate merely replied that she had done him a favor and repaid her with a fight.
Hayate encountered Hitomi once again, who pleaded for him to come back with him to the dojo, admitting that she did not know what to do without him. Hayate told her that he couldn't because he was no longer Ein, and the fourth tournament was no tournament at all, but a war between DOATEC and his people. He then asked her to spar for a warm-up, for old time's sake, which she happily accepted. After the fight, they told each other to take care and Hitomi took her leave, obviously upset by the parting.
In the end, Hayate joined up with Ayane again, and they tried to fight their way out as Ayane's Art of the Raging Mountain God spell starts to burn down the building. As they tried to leave, they were set upon by Alpha-152, the now-enhanced, new form of Kasumi Alpha. Despite the clone's strength and super-power abilities, the two shinobi managed to escape it and the Tritower complex as it burnt to the ground.
Dealings with DOATEC and the Attack on the MIST LaboratoryEdit
For the next two years the Mugen Tenshin Ninja Clan would know relative peace. One day, Helena, DOATEC's new President and CEO, gives Hayate an invitation to the luctury yacht Freedom Survivor. Transported there by Zack, he wonders what Helena wants from him. Zack jokingly tells him that maybe she was setting him up with someone, although Hayate initially took it wrong. Zack corrects himself explaining he was to have a meeting with her. In the Executive Office, he meets his sister Kasumi. Helena considers it an honor to have the eighteenth Master Ninja of the Mugen Tenshin in her presence, and proceeds to explain to him that Kasumi's clone, Alpha-152 is still at large, and that it would be too dangerous for Kasumi to do alone. Kasumi asks him to listen to her, that the Alpha affair was her mess alone to settle. However, Hayate agrees with Helena, saying that this whole issue is not just about her anymore, but the safety of their whole family and clan. But Kasumi runs out, saying that it was her fight alone. Hayate follows her and senses something was amiss. His youngest sister Ayane comes forth and lets him know that she's sensing something foul about Kasumi too. Hayate orders her to follow her, and find out her true intentions.
Sometime later, Hayate is met by his best friend Ryu at the Ryugaku Temple. Hayabusa criticizes him for not being able to handle Kasumi provoking him to fight each other but he was defeated; after the battle, the Master Ninja told him that don't let his emotions cloud his judgement.
A few days later, he meets Bayman in the Middle East, and wonders what he was up to. Bayman tells him that he and Hayate are both looking for Kasumi for answers and they fight about it in hand-to-hand combat. Zack interrupts their battle, telling Hayate that Helena needs to talk about something important.
At the Freedom Survivor Helena tells him about a group called MIST. This group, according to her, were inside of DOATEC before they had a formal name, and that the Alpha project is in its final phase: Phase 4, which is the production and distribution of super soldiers to their clients, the militaries of the world's dominant nations. Hayate is infuriated to learn that he, his family and his clan were used for the sole purpose of profit for Donovan. Helena Douglas tells Hayate that she has sent Kasumi to the Offshore Platform because of uncanny comings and goings from Miyako, Christie and Lisa Hamilton. He, Ryu and Ayane head over there to stop Donovan's plans.
During the fifth tournament, Hayate reunites with Hitomi, who proudly tells him that she's in the finals. He has a friendly spar with her to prepare her for her final match. Then he leaves with Ayane, but wishes Hitomi good luck.
The two Mugen Tenshin ninja find Bayman again, who is infiltrating the rig to find Kasumi. Hayate fights him to see who will deal with his sister and wins. Bayman then helps him and Ayane find Kasumi and they confront her, who was in reality a Kasumi Alpha clone programmed into thinking that she is the original.
After killing the clone, Hayate, Bayman, and Ayane head to deeper into the platform. Taking an ID card off of a scientist they assassinated, They discover the platform was actually a cover for MIST's operations. Bayman tells the two ninja to carry on without him and finish the battle. At the lowest level, Hayate and Ayane confront Rig. The hooded man taunts Hayate into a battle who emerges victorious, but suddenly, the ninja is impaled with beams of light. As he is captured by Rig, Ayane is forced to flee to warn Ryu. As the real Kasumi appears to rescue him, Lisa appears and realizes that Donovan is reactivating Project Epsilon proceding to override the process when he activates Phase 4. After the scientist frees Hayate, the ninja destroy Alpha-152 and escape the crumbling facility back to the Freedom Survivor.
After Kasumi gives her thanks to him, Hayate watches with Ayane and Ryu as she leaves to defeat Donovan.
In Dead FantasyEdit
Hayate interrupts Hitomi's duel by sending his ninjas to kill her opponent, Tifa Lockhart. His ninjas manage to corner Tifa in a warehouse, but ultimately fail to defeat her. Despite being greviously injured by his men, Tifa attempts a final charge at Hayate, but he puts her down for the count with a lightning-fast punch. He brings Tifa's unconscious body to a helicopter where Helena waits to take her back to DOATEC. When Hitomi catches up with him, she sees him carrying a very battered-looking Tifa. Hitomi is visibly upset, and slaps him across the face, to which he shows no response. When placing Tifa on the stretcher, Hayate briefly reads her recent memories (as his hands are positioned similar to Momiji's when she read Kasumi). After Hitomi and Helena take Tifa into the helicopter, Hayate stares down at Tifa's blood on his palm, a gesture fans interpret to mean he feels guilty of his actions.
On Sora's TeamEdit
Hayate joins the team after meeting Riku and he also encourages his sisters to join the team and help defeat all their enemies and save there worlds.