Ryu Hayabusa

Ryu Hayabusa (Japanese: 隼 龍 Hayabusa Ryū) is a superior shinobi, and the star of the Ninja Gaiden series. He first appeared in the original Ninja Gaiden but later appeared as a consistent character in the Dead or Alive series, which sparked a renewal of the Ninja Gaiden franchise as well.

A member of the Hayabusa clan’s head family, Hayabusa often takes on the leadership responsibilities of the clan and the protection of the Dragon Sword while his father Jô Hayabusa trains in the mountains. He was the winner of the second Dead or Alive Tournament.

Background

 * For more information, please visit Ryu Hayabusa's page on the Ninja Gaiden Wiki.

The son of Jô Hayabusa, Hayabusa was born into the Dragon Lineage legacy; as required, he would be trained from childhood to walk the path of a ninja, a way of life plagued with danger, pain and sorrow.

He would become the youngest Dragon Ninja in his clan's history at the age of 21 years old, with skills rivaling that of many Master Ninja. Coupled with his talents in combat, stealth, and the mystic arts, his strength and ability against foes on missions that would be considered insanity by a normal person or shinobi's standards would be recounted in countless tales as the "Solitary Super Ninja."

The First Tournament
Hearing that Kasumi had run away from her village to seek vengeance for Hayate, Hayabusa tracked her to the Dead or Alive Tournament, where he joined the tournament as a participant in order to keep an eye on her. When Raidou and Kasumi had a ninpo energy duel using the Torn Sky Blast, Hayabusa threw a kunai into the genetically altered rogue ninja's arm, distracting him long enough for Kasumi to kill him with the ninpo. But as soon as the dust cleared from the following explosion, Hayabusa discovers that Kasumi had been captured and leaves to find her.

The Second Tournament
Hayabusa entered the second Dead or Alive tournament in order to confront and defeat the renegade Tengu Bankotsubo, who had somehow managed to escape into the Human Dimension from the Tengu World. After getting close to DOATEC scientist Lisa and taking her ID card, Hayabusa meets with Irene and infiltrates the DOATEC Germany lab in the Black Forest of Germany. There he finds Kasumi and rescues her from Lisa and Kasumi's clone Kasumi α.

Thanks to the data he retrieved from the lab, he and Irene piece together the connection between Raidou's inhuman strength and Alpha. To both of their surprise, the Epsilon Project resurrected Hayate from his comatose state. Kasumi tries to go after Hayate despite Hayabusa's stand against it. He tried reminding her that she is a Shinobi and that she had to think rationally, but her emotions for her brother caused his words to fall on deaf ears, and Hayabusa is left with no choice but to send Ayane after her.

Meanwhile, Hayabusa tries to warn the other competitors about the danger of DOATEC but finds them unwilling to backdown so he proceeds to knock them out of the contest. Eventually he meets Ein, who is actually the missing Hayate suffering from amnesia. After Hayabusa defeats him and restores some semblance of his memory, Hayabusa sets off to face the Tengu of Destruction himself before he could cause anymore damage. Hayabusa bests the mad Tengu in hand to hand combat, killing him and preventing his madness from spreading.

Hayabusa reunites with Hayate and Kasumi and, with encouragement, the two battle as siblings, reviving Hayate's memory in the process. But all was not well yet, as their reunion was interrupted by Genra of the Hajinmon sect. Genra reveals himself as the one who broke the barrier and summoned Bankotsubo and then sicks Ayane, possessed by Genra's Genjutsu to fight the two shinobi masters. Alpha joins the fight but the two emerge the victors. Hayabusa then introduces Hayate to Irene and fills his best friend in on the DOATEC issue.

The Third Tournament
Hayabusa sits on the roof of Azuchi on a moonlit night. He says that Hayate couldn't possibly defeat Genra but Hayate tells him he doesn't know Genra at all. Hayabusa tests Hayate to see if he remembers everything. Hayate appears to beat him, only to realize Hayabusa used the Kawarimi technique to trick him at the last second. Hayabusa tells him that he and Hayate can settle their bout in the third tournament.

Later Hayate and Hayabusa restart their fight. Hayabusa initially plays around with Hayate and then he fights him seriously. Things heat up extremely when the two use their strongest ninpo techniques but the fight is interrupted by Ayane, who alerts Hayabusa to Irene's kidnapping by Christie. After defeating the assassin, Hayabusa realizes that it was a diversion and rushes to Hellfire to save his friends. As Genra, in his monstrous Omega form, prepares to deal the fatal blow to Hayate and Ayane, Hayabusa throws a kunai into his helmet and slashes him with the sacred Hayabusa ninja clan relic the Dragon Sword. Using all the strength he can, he buys time for the two Tenjin Ninja to use a dual Ninpo to end the fight, killing Genra in the process as Hayabusa rolls to safety.

The Fourth Tournament
Invited to participate in a group offensive, Hayabusa joins Hayate, Kasumi, and Ayane to stop DOATEC during the fourth tournament. Hayabusa and Ayane come across Christie, who was trying to stop the ninjas from destroying the DOATEC Tritower. However, her attempt fails and the building falls from the detonator Helena Douglas set off. Hayabusa also saves Kasumi from being shot by Helena and later encourages her to fight her clone Alpha-152, which he thought was her fight alone.

Attack on the MIST Laboratory
Hayabusa meets with Hayate at Ryugaku-ji and criticizes him for not being able to handle a nukenin, calling him a failure as the 18th Master of the Mugen Tenshin clan and infuriating the Wind Ninja to battle him. Hayabusa defeats him, telling that he mustn't act hastily on emotion and go carefully. A few hours later in Tokyo, Hayabusa listens to Lisa Hamilton talking on her cell phone and learns about Donovan's new organization: MIST. Hayabusa confronts Lisa and chastises her for continuing her heinous experiments, but she tells him that as a scientist, it is her duty to make important discoveries. An angered Hayabusa scoffs at this, saying that her "discoveries" have only brought about suffering for his friends and brought him to his own cursed karma as a Dragon Ninja, prompting him to do battle with her and win the fight (unknown to him, their fighting causing a construction site to collapse and fall into a city, where Kokoro was watching the fifth tournament announcement). The next day, in New York, Zack, working for the newly reformed DOATEC, pleads with Hayabusa to go see Helena for a meeting in her ship. The Dragon Ninja says that he'll see her when his business is finished, refusing to get into the helicopter and provoking Zack to fight against him. Hayabusa emerges victorious.

Later, he reaches the Freedom Survivor and reunites with Hayate and Ayane. They learn from Helena that MIST was most likely inside DOATEC before and that Donovan's Alpha plan is at Phase 4: to create super soldiers that have the fighting capabilities of the ninja and sell them to countries with powerful militaries to make a profit. Knowing that they need to stop Donovan, the three ninja head for the oil rig, where Helena believes it to be where he's conducting his experiments. After Hayate and Ayane kill Kasumi's clone, Hayabusa watches her death, commenting that she still had a life like any other, no matter how cruel it was, and ask himself why Donovan is trying to reunite his friends for a dangerous mission. When Hayate is captured by Rig and Ayane reports to Hayabusa about it, the Dragon Ninja sends his falcon to deliver a message to the real Kasumi, who is waiting back in Japan with Muramasa on a hidden village and prompts her to join the battle. After she infiltrates the lab and Lisa rescues Hayate, the four ninja destroy the lab and defeat Phase 4 (although it doesn't have a name and can transform into Kasumi, Hayabusa, Ayane, Hayate.)

Afterwards, Hayabusa, Hayate, and Ayane watch on the Freedom Survivor as Kasumi leaves to defeat Donovan.

Appearance

 * See also: Hayabusa's costumes

Hayabusa is the epitome of a present day ninja: his Legendary Black Falcon outfit's sleek design is similar to that of the modern special ops agent, while the tabi boots, ninja head piece, mask, scarf, and shin/forearm guards are reminiscent of the ancient ninja warrior. His classic Ryuken outfit sports a traditional ninja uniform with a slight 80s twist. The Hayabusa clan standard black ninja uniform Hayabusa initially wears is the most traditional of his ninja attire.

Physically, Hayabusa is a young man in his mid 20s, standing at 179 cm (5' 10"), and weighing in at 78 kg (172 lbs.). He is in peak physical condition with a muscular build. As a ninja, most of his costumes and attire conceal his face, revealing only his eyes, one of his most distinctive features. Hayabusa's eyes feature light green coloration with a slight golden hue and an Asian shaped epicanthic fold. This golden hue feature is more prominent when accompanied by his wardrobe, which is composed of mostly dark colors, something that points out even more of his peculiar eyes and gives him an intimidating appearance.

Underneath the ninja mask and hood reveals a youthful face and long dark brown hair that is usually tied back in a waist length ponytail, a completely opposite appearance to what many would expect, given his deadly skills and calculative, savage brutality in battle.

Personality
Hayabusa has the demeanor and wisdom of a man far older than himself, due to his prolific lineage and mantle of station as a respected ninja. His exploits have given him an attitude far removed from most others and he understands things in more abstract and philosophical terms. Much like Gen Fu and Eliot, he adopts a tranquil nature; free flowing most of the time but unforgiving and crushing when roused. Through the Dead or Alive tournament, he has extricated himself from many of the subplots involving other characters, concentrating instead purely on the larger goals that present themselves.

He is Hayate's best friend and an ally of Kasumi and Ayane. He and his ninja brethren have been direct players in the defeat of every major threat in the DOA tournaments, himself defeating the rogue Tengu in single combat during the second tournament. Hayabusa has befriended several people from the DOA tournaments, notably Jann Lee, with whom he shares a mutual respect.

In his appeals he shows his shinobi side, but at the same time he shows a traditional respect. Sometimes, though, he will smack talk his opponents, saying they can't distract him when they fight, and in his victory quotes he affirms he has no weakness and that nothing can hinder his spirit, showing that he refuses to let any insecurities cloud his mind and won't tolerate weakness in himself.

Etymology
The kanji used to spell Hayabusa's first name "Ryu" (龍) means "dragon." Hayabusa's surname (隼) means "peregrine falcon." Hayabusa's name alludes to his ancestry, as he is descended from an ancient Ninja lineage that has formed a covenant with the Hayabusa-no-kami (隼の神; The Spirit of the Falcon) that guards the spiritual forests of Aokigahara Forest near Mt. Fuji, and Ryu alludes to his Dragon like nature; usually kind, wise and philosophical and gentle, but wrathful and fatally ruthless when angered.

Hayate/Ein
Hayabusa and Hayate are good friends. They are both the same rank and intelligence and are as close as brothers. Hayabusa is very protective of his friends so he watches over Hayate, too. In Dead or Alive 3, Hayabusa decides to destroy Genra to keep Hayate safe. At Hayate's request, Hayabusa watches over his younger sister Kasumi, hence why he is always by her side. In Dead or Alive 2, Hayabusa is the first person Hayate (under the name of Ein) was able to remember after suffering amnesia. He advises him to find Kasumi and fight her in order to get his memory fully restored. Often a big brother figure to Hayate, he will tend to tease him when they spar, but he will talk down to him when he knows he's being careless, or acting on hasty feelings, much to the latter's irritation.

Ayane
Hayabusa and Ayane have worked together on many occasions; five if counting the Tengu affair in the second Dead or Alive tournament, the Omega affair, and the Mugen Tenshin’s attack on DOATEC. Since the Dark Dragon Blade incident, the two seemed to have formed a friendly working relationship, with each recognizing the other’s skills and capabilities. She regards Hayabusa with respect and has formed a working relationship with the Dragon Ninja. As of Dead or Alive 4, they share tag team animation, much as Hayabusa and her half-sister do in other games.

Kasumi
As a family friend, Hayabusa is a good friend to Kasumi as he watches over her and tries to protect her from harm during Hayate’s recovery/absence. Her strong-willed nature does prove to make this difficult at times, however, such as when she entered the Dead or Alive tournament, forcing Hayabusa to also enter if he was to continue keeping an eye on her. He tries to stop her in Dead or Alive and Dead or Alive 2, but fails. He doesn't see her in Dead or Alive 3 due to her departure against his wishes, but in Dead or Alive 4, Hayabusa saves her from Helena's attempt to kill her. In Dead or Alive 5, it is presumed that Hayabusa is the one who has Muramasa watch over Kasumi to keep her safe before the battle against Alpha-152 in the MIST laboratory.

As of Dead or Alive 2, they are one of the most compatible tag teams in the series - always sharing tag team animation sequences. They have one tag each towards each other, one pre-animation sequence, and one win sequence. In Dead or Alive 5 tag battles, they maintain everything in the tag union, but now they call for each other when tagging.

In the 2006 live action movie DOA: Dead or Alive, it is implied Kasumi may have romantic feelings towards Hayabusa and that the feelings may be mutual - though he is reluctant to show it (presumably since it would be a forbidden relationship).

Lisa Hamilton
Lisa and Hayabusa's relationship is that of one-sided irritation. When first they met Hayabusa posed as an onlooker on the DOATEC Yacht, the Freedom Survivor, looking for the captive Kasumi. After managing to get close to Lisa, who tried to flirt with him at the time, he stole her DOATEC ID while she showered, heading for Germany where Kasumi was being held. When Lisa held her at gun point, Hayabusa intervened and caused her to flee. Two years later he found that Lisa had been in contact with Donovan, continuing his inhuman science projects. Hayabusa was angered, as DOATEC's and by extension her own actions, lead to the Mugen Tenshin clan suffering immensely.

Jann Lee
Though Hayabusa has befriended several people from the Dead or Alive tournaments, Jann Lee is notable since the Tengu incident onwards due to their gradual recognition and respect for each other’s abilities despite Jann Lee being a civilian. By the events of Dead or Alive 4, They have formed something of a friendly rivalry. Jann Lee demonstrated his mastery in nunchaku. He threw them to Hayabusa in which he showed complimentary mastery. The two engage in a friendly spar with him in the fourth tournament.

They have been a full tag team alliance since ''Dead or Alive 2. ''One tag consists of Hayabusa leading by launching the opponent into the air, then lifting Jann Lee into a sky-high flying side-kick. The second is where Jann Lee is leading the duo, with twin kicks to the opponent's head, propelling them into the surrounding environment.

Momiji
Momiji is the last of the Hayabusa clan's shrine maidens and Hayabusa's apprentice. After the death of her sister and the massacre of the Hayabusa village during the Dark Dragon Blade incident, she trained under the protege of Ryu Hayabusa. A prodigy in the ninja arts, Momiji has grown to be an exceptional kunoichi in her own right. Enamored with his convictions, Momiji shares Hayabusa's perceptions of virtue and justice, only resorting to deadly violence against her clan's enemies. She looks up to her master with pride as both a mentor and an undying ally, and Hayabusa is equally proud of his disciple and sister-in-arms, having her accompany him on missions.

Rachel
Hayabusa and Rachel's relationship was initially complicated due to Rachel's coldness towards Hayabusa, while Hayabusa didn't like Rachel when she was testing him during the Dark Dragon Blade Incident in Ninja Gaiden. Despite their differences and ideals, the two have come to mutual terms, forming a working relationship as well as a close friendship, and slay the evil Fiends together whenever they meet, with Rachel slowly beginning to trust Hayabusa over time because of him rescuing her from enemy capture multiple times while she was on a crusade to slay her own twin sister, who had become evil due to the fiend blood in her veins. Her respect and admiration for Hayabusa can be seen in Dead or Alive 5 Ultimate when she says he's like having the strength of a hundred others.

Irene Lew
Irene's first encounter with Hayabusa is in the original Ninja Gaiden, where she shoots and captures him with a tranquilizer dart. She gives him the Shadow demon statue and is later taken hostage by the Jaquio in order to force Hayabusa to hand over the statue. Although Hayabusa complies, the Jaquio keeps Irene to be sacrificed and drops Hayabusa into a pit. However, Hayabusa manages to find a way out and defeats the Jaquio, escaping the collapsing temple with Irene. Irene disobeys an order from Foster to kill Hayabusa, and the two end up becoming an item, running a curio shop together over time. In the current reboot of Ninja Gaiden, she went under the alias "Sonia," assigned to assist Hayabusa in keeping the Necromantale order from reviving an ancient demon lord his ancestors sealed away. In Ninja Gaiden III, she is mentioned when she sends a communication to the location of the LOA group's Black Narwhal vessel, under the signature "Sea Swallow." Hayabusa instantly recognized it because Irene told him that was her codename. She's also implied to be an item with Ryu, but neither of them confirm nor deny it, preferring to keep their friends in suspense with Ryu talking professionally in Dimensions, or Irene just saying she knows Ryu better than some of his friends in Ninja Gaiden III: Razor's Edge (humorously to Ayane's annoyance.)

Muramasa
Muramasa is one of Hayabusa's valuable allies because he provides weapons, upgrades and supplies for the ninja. Whenever he needs help, the ninja can always count on Muramasa. Muramasa has been a friend of the Hayabusa family for quite some time, and always tries to help Ryu when he can.

Naotora Ii
Although it is unclear if he ever encountered Naotora Ii face-to-face, he has at least heard of her, as he mentioned that he recognized her from reading ancient scrolls detailing the Warring Period of Japan. In Warriors All Stars, they interact with each other sometimes in the game and both respected and admires each other's skills and capabilities in battle. They are both fighting on Shiki's forces along with Ayane.

Gameplay

 * See also: Hayabusa's command lists

Hayabusa is arguably a top-tier character, both due to canon and gameplay. He was nerfed in Dead or Alive 5 Last Round, but his holds and throws are all still above-average. Additionally, Hayabusa's unbreakable Izuna-Otoshi combo throw is one of the most powerful in the game and variations of it can be performed: from a crouching throw (Yoko-Izuna), from a strike (Shoho-Izuna), and from his expert holds (Senko-Izuna, Rekko-Izuna, Yoko-Izuna), although sometimes a combo from his Izuna throws and holds may be more effective in certain situations. His mix-ups and surprise attacks (like his Asuka-Gaeshi) keep many players guessing which angle or height he will strike from next.

However, he is one of the more difficult characters to learn as he requires strong and good execution, has a bad neutral game, and is also a high risk, high reward character. Whilst he also has an effective force tech (Rekku-Utsusemi) that allows him to teleport to the back of the opponent, leaving the opponent vulnerable while giving him an advantage, it is also risky as it will leave him with his back turned against the opponent should the move unsuccessfully connect with a grounded opponent.

He is also apparently the slowest ninja just after Raidou, lacks decent mix-ups and he also lacks a lot of low strikes to open up the opponent. His strings also lack a lot of tracking (One notable example is the Shoryu kick, which is extremely linear to the point where you can avoid it and have yourself facing Hayabusa's back by just free stepping in close range) and they are also rather unsafe. His only parry from the Ongyoin stance, while it puts him on the other side of the opponent, is rather unreliable compared to the parries of other characters, as the frame advantage he gets from a successful parry is dependent on the recovery of the parried opponent's move, so it is possible for him to not gain any frame advantage at all. He only makes up for his weaknesses with good wall and environmental game, deep stuns, and his high damage output, but only if he is able to open up the opponent.

He possesses a few offensive holds which other ninjas are lacking (except Raidou) and his throws have the speed of a grappler. His Ongyoin stance, which is significantly more useful in Dead or Alive 5 and its iterations gives him more moves to choose from, such as an unbreakable combo throw, a teleport parry, an offensive hold and teleport strikes. However, the weakness of the Ongyoin stance is that most of its long distance attacks are linear, which means they could be evaded effortlessly by free stepping or side stepping.

Some of his throws and moves that can help maximise his damage output include the first kick of Shoryu-Tenda/Shoryu-Tenho/Shoryu-Kyaku, Urakaze; his air throw (Koryuho) and the Shoho-Izuna, which is even more effective in stages with ceilings (Zuisho-Izuna).

Stats
The following are Hayabusa's official stats as listed in the games.

Dead or Alive series

 * Dead or Alive games (playable, 1996-98)
 * Dead or Alive 2 games (playable, 1999-2000)
 * DOA2: Hardcore games (playable, 2000)
 * Dead or Alive 3 (playable, 2001-02)
 * Dead or Alive Ultimate games (playable, 2004-05)
 * Dead or Alive 4 (playable, 2005-06)
 * Dead or Alive Xtreme 2 (mentioned, 2006)
 * Dead or Alive Paradise (mentioned, 2010)
 * Dead or Alive Dimensions (playable, 2011)
 * Dead or Alive 5 (5+) (playable, 2012-13)
 * Dead or Alive 5 Ultimate (playable, 2013)
 * Dead or Alive 5 Ultimate Arcade (playable, 2013)
 * Dead or Alive 5 Last Round (playable, 2015)
 * Dead or Alive Xtreme 3 (mentioned, 2016)
 * "Dead or Alive 6" (Playable 2019)

DOA: Dead or Alive
Hayabusa appears in the 2006 movie DOA: Dead or Alive, portrayed by Kane Kosugi, where he performs a role similar to the games. In the movie, Hayabusa is shown as a faithful friend to Kasumi and Hayate.

Dynasty Warriors: Strikeforce
Hayabusa makes a guest appearance in version of Dynasty Warriors: Strikeforce. He is an NPC that offers three different quests to the player. If the player manages to complete all of the challenges he gives them, they earn the right to wield the Dragon Sword in battle. Its attack pattern is similar to the Curved Sword move-set that appears in the game but with its own unique special attacks taken straight from Ninja Gaiden Sigma 2.

Warriors Orochi 3
Hayabusa also appears in the Tecmo Koei hack-'n-slash game Musou Orochi 2 (Warriors Orochi 3) as a playable character, representing the Ninja Gaiden series. He is one of five guest characters, staring alongside Joan of Arc, Achilles, Ayane, and Nemea. Hayabusa appears in his own stage that depicts Kyoto as it is seen in the beginning of Ninja Gaiden 2 merged with a historical Japanese battleground known as Anegawa.

According to comments from Team Ninja developers, he (along with Ayane, Rachel, Momiji, and Kasumi) arrives in the dimensional realm before the events of Ninja Gaiden III, as well as after Dead or Alive 4.

Warriors All-Stars
In an alternate world that relies on a miraculous spring to sustain itself. The King who could control the spring's powers suddenly perished, leaving the world in turmoil. The Queen told her daughter, Tamaki, to summon otherworldly heroes to save their land, but the attempted summoning malfunctioned and left them scattered in different areas. Eventually, other members of this royal family are deemed eligible for the throne, dividing all the heroes into three warring factions.

He represents the Ninja Gaiden franchise, although due to its ties to the Dead or Alive franchise, he also has character interactions with Kasumi, Ayane, Marie Rose, and Honoka.

ZEN Pinball Ninja Gaiden Sigma 2
Hayabusa appears as part of the deco of this specialized pinball series for the PlayStation Network and also features on its logo.

Nioh
Though Ryu Hayabusa did not appear in Nioh, a bonus ninja boss character named Jin Hayabusa shares similar traits as Ryu, such as wearing Ryu’s first appearance outfit from NES version Ninja Gaiden, and even have some of Ryu’s fighting style such as the signature Izuna Drop.

Outfit usages
The style of Hayabusa's shinobi outfit appears as an unlockable SPARTAN armor type in Halo 3 known as "Hayabusa." Used in multiplayer, the armor is unlocked by collecting thirteen skulls for the helmet, nine skulls for the shoulder armor, and five skulls for the chest armor.

Furthermore, if the 1000 gamerpoints are obtained from the Halo 3 achievements, a replica of the Dragon Sword can be obtained. However, it cannot be used as a weapon, only acting as an addition to the armor.

His suit also appears as an optional costume in . Parts of Ryu's Ninja Gaiden outfit also appears as special costume DLC for PS3 owners of Dynasty Warriors: Online for their character.

The outfit also was used in Phantasy Star Online 2 as part of a collaboration between that game and Dead or Alive 5 Last Round.

Dead Fantasy
Hayabusa appears as a combatant in the fan-made CG movie series Dead Fantasy, where fighters of the Dead or Alive series battle cast members from the Final Fantasy franchise. He uses the Dragon Sword and fights alongside Momiji. Ryu's main opponent is Vincent Valentine from Final Fantasy VII.

Since Oum's death, the series' future is left uncertain.

Fighting quotes

 * Dead or Alive/Dead or Alive 1 Ultimate
 * Dead or Alive 2/DOA2: Hardcore
 * Dead or Alive 3
 * Dead or Alive 2 Ultimate
 * Dead or Alive 4
 * Dead or Alive Dimensions
 * Dead or Alive 5
 * Dead or Alive 5 Ultimate
 * Dead or Alive 5 Last Round

Music themes
The following are the music themes used for Hayabusa throughout the series.

Note that both the Dead or Alive++ and Dimensions themes have no official names.

Gallery

 * See: Ryu Hayabusa gallery

Trivia

 * In the original Dead or Alive, Hayabusa was supposed to be a new character named Kamui but one of the staff members suggested featuring Ryu Hayabusa and his persona was added to the roster. In the Sound Test of Dead or Alive and Dead or Alive 2 arcade versions, his BGM and dialogue still use the two-letter code "KM". It is likely that the staff suggested Ryu because the original character's name was a tad too similar to the name of Kasumi and it would have gotten confusing.
 * Hayabusa's eyes became green, contrary to the brown eyes from Ninja Gaiden (NES). Itagaki revealed in the interview with Famitsu that this change was made because "the green eyes looked cool on Ryu".
 * Zack is shown to be a regular customer at Hayabusa's curio shop, shown through the items shown in Dead or Alive Xtreme Beach Volleyball and Dead or Alive Xtreme 2.
 * His appearance in the original Dead or Alive is his only appearance in the series where he doesn't wear either his "Legendary Black Falcon" outfit or his traditional shinobi robes.
 * Hayabusa is mentioned through Dead or Alive Xtreme 2 and Dead or Alive Paradise through Ayane as the player interacts with a golden scarab.
 * Hayabusa's lose pose animation in Dead or Alive 5 involves him holding his right arm in pain. This is a reference to how his arm got cursed in Ninja Gaiden 3.
 * His live-action actor, Kane Kosugi is also known playing another black ninja hero, Jiraiya/Ninja Black of Super Sentai series' Ninja Sentai Kakuranger. Like Ryu, Kane also studies Ninjutsu, as it was taught to him by his father, famed Ninja actor Sho Kosugi.