Kurama

, more commonly known as the, is a tailed beast currently sealed within Naruto Uzumaki of Konohagakure. The fox was first sealed into Mito Uzumaki after the battle at the Valley of the End, then into Kushina Uzumaki after Mito's death.

Background
Kurama first came into being in the waning days of the Sage of the Six Paths, who used his Creation of All Things ability to separate the Ten-Tails' chakra from its body and divide it into nine separate constructs in order to ensure that it would never resurface after his death. Some time after being created, the Sage sat down with all the young tailed beasts and told them that they would always be together even when separated, and that one day they would become one entity again with different names as well as forms than they did then when the time came for them to understand what true power is. Over the centuries, Kurama has gained a reputation as an age-old natural disaster, appearing suddenly out of nowhere to attack areas that have breeding grounds for the darkest aspects of human nature.

At one point during the time of the formation of the shinobi villages, the Gold and Silver Brothers of Kumogakure were assigned to capture Kurama, but they were both swallowed whole by the fox. However, the two brothers managed to survive and gain some of its power by eating the flesh of its stomach for two weeks, which caused Kurama to regurgitate them.

After that event, when Madara Uchiha defected from Konoha, he used his Sharingan to control and use Kurama to help him fight against Hashirama Senju, the First Hokage, to exact his revenge. The battle was so great, it created a vast crater that later became known as the Valley of the End. Despite being in control of Kurama, Madara was defeated and was believed to have died. After the fight, Hashirama's wife, Mito Uzumaki, sealed Kurama within herself, becoming its first jinchūriki.

For over the period of the first two Shinobi World Wars, Mito kept Kurama at bay except on one event when the seal had begun to weaken as she was going through childbirth. Towards the end of her life, Mito passed on this status and responsibility to another member of her clan, Kushina Uzumaki, who later became the wife of Minato Namikaze, the Fourth Hokage. Though Kushina was terrified with the responsibility of containing Kurama, Mito assured her successor that the fox's malice was powerless against her love.

Twelve years before the start of the series, after the end of the Third Shinobi World War, the Third Hokage and his wife made preparations to ensure that Kurama would remain sealed within Kushina as she gave birth to Naruto. However, despite keeping her childbirth a secret, Tobi discovered Kushina's location, killed her escorts and managed to break the seal, seizing control of Kurama. Since Kushina survived the extraction, Tobi tried to have Kurama kill her before Minato got her and their son to safety. Soon afterwards, Tobi summoned Kurama into Konoha and ordered it to destroy the village.

While Kurama was rampaging in the village and decimating the shinobi forces that tried to repel it, Minato managed to place a Contract Seal on Tobi during their fight to free the fox from the masked man's control. Before Kurama could annihilate Konoha out of sheer revenge, Minato summoned Gamabunta on top of the fox, and later teleported it to Kushina and Naruto's location, while letting its Tailed Beast Ball detonate away from the village. Soon afterwards, Kushina used her chakra chains to subdue Kurama, planning to seal it back inside her before she dies. However, Minato, knowing that Kurama would revive without a host and a threat Tobi still was to the village, came up with a different plan to give Konoha the means to combat Tobi if he should ever attack the village again.

Since Minato himself couldn't fully seal Kurama as it was, he used the Dead Demon Consuming Seal to seal its Yin chakra within the death god and then prepared the Eight Trigrams Seal to imprison the fox, along with its Yang chakra, within Naruto. Kurama realised Minato's intention and attempted to stop the process by killing Naruto while Kushina was weakened, but both the parents sacrificed themselves to protect their newborn child and complete the sealing, with Kurama cursing the pair during its last moments of freedom.

In the anime, it was revealed that Kurama had left behind large amounts of its chakra during the attack. Kazuma collected and sealed the chakra within his own son, Sora, hoping to make use of its power for his own agenda.

Personality
Kurama is characterised as cynical and shrewd, with a distinct sense of honour and pride. It uses when referring to itself, which is generally used by older men. In a flashback, it is revealed that Kurama cares greatly about the Sage of the Six Paths, viewing him with great respect for the way he treated the tailed beasts and even shed tears after the Sage had imparted his final words to them. However, this sentiment was not extended to its brethren, as Gyūki mentioned that they, especially Shukaku, hated Kurama for its belief that their strength is determined by their number of tails. Kurama even told Naruto that he should be ashamed for having Gyūki help him in their battle over its chakra.

Because of its long history of both its forced subjugation to the Sharingan and being sealed within the Uzumaki jinchūriki, Kurama expressed intense hatred and distrust for humans, even showing its animosity toward Naruto whenever they communicated. The two had a very antagonistic relationship throughout most of the series, with Naruto trying to harness the fox's power to perform techniques that would normally be impossible for a ninja of his age, and Kurama seizing any kind of opportunity to gain control over Naruto, provoking his rage and thus allowing its influence within its chakra to consume him. This status quo would remain between the two until the Fourth Shinobi World War, when Naruto, with the help from his mother, defeated Kurama and took control of its chakra.

During their first conversation after taking its chakra, Kurama was shocked to hear Naruto wanting to do something about its hatred. Although the fox reproached him for making such a claim, it nevertheless showed Kurama that Naruto was different from the humans it previously encountered, which made it stop consuming Naruto's chakra while he was using his Nine-Tails Chakra Mode, allowing Naruto to keep on fighting throughout the night of the war. Later, while the reincarnated Madara Uchiha was fighting against one of Naruto's shadow clones and the Fourth Division, Kurama, while claiming to only be helping Naruto because he was a better alternative than the reincarnated Uchiha, gave Naruto enough chakra to repel his attacks. Afterwards, in Naruto's battle against Tobi and his Six Paths of Pain, Kurama — having witnessed the challenges and endeavours Naruto had in his life, and heard his intention of helping the tailed beasts — silently told Naruto that if he truly meant to do that, he would have to prove it through his actions, not his words. When Naruto successfully freed Son Gokū, Kurama offered to meld its chakra with his as a coalition, to which Naruto then removed the seal that restrained it and happily acknowledged the fox as his partner. In that short space of time, the two have built a trusting relationship with one another, even to the point where Naruto would allow the fox to take control of his body without worry, and switch back without hesitation. Kurama would later admit that it had the utmost faith in Naruto being able to defeat Tobi and to carry on the legacy Minato and Jiraiya had left him. Kurama no longer seems to hold a grudge against Minato for sealing it inside of Naruto and even seems to be happy about it now.

Appearance
Although Kurama is a kitsune with red-orange fur and red eyes, it possesses the upper-body structure of a human, complete with opposable thumbs on its clawed hands. Out of all the tailed beasts, Kurama's form most closely relates to the Ten-Tails'. During the last remaining days of the Sage of the Six Paths, Kurama was a young kit much smaller than its present-day self, but was still much larger than the Sage. As time passed, Kurama's size increased to be around the same height, if not taller, as the Hokage Monument. Later, despite shrinking a lot after having its Yin chakra sealed, it still remained a massive entity as its claw dwarfed Minato and Kushina. When Naruto separated Kurama from its chakra, its entire physique became visibly emaciated, but it later regained its healthy look after consuming a certain amount of Naruto's chakra while he was using its own.

After having its cage opened by Naruto — who had assumed a new form — this is also reflected on Kurama, when Naruto transforms into it. In this form, the fox's whiskers become much thicker, and circular markings appear on its shoulders, stomach, as well as the front and back of its paws. Lines also run down its spine, arms, legs and tails.

Abilities
Being the strongest of the nine tailed beasts, it is said that Kurama can create tsunamis and flatten mountains with just a single swipe from one of its tails. With its massive supply of chakra, it can turn its roar into a powerful shockwave that can repel and destroy anything within its radius, increase its physical strength and speed, and fire Tailed Beast Balls. Kurama also has the ability to sense negative emotions, to which Naruto also gained after gaining control of its chakra. In the anime, it was shown to be able to create twisters and breathe fire.

Despite losing its Yin chakra, Kurama was more than powerful enough to overwhelm Gyūki's attempts to restrain it (although Killer B stated that he didn't have full access to his own powers within Naruto's subconscious), effortlessly block Naruto's Sage Art: Ultra-Big Ball Rasengan with its tails, and — with Gyūki's assistance — fight and defeat five tailed beasts. Naruto also noted that it was extremely fast despite its massive size. In addition, it was shown that even when most of its chakra was taken by Naruto during their battle in his subconscious, Kurama still had enough to create a Tailed Beast Ball as big and powerful as that of a combined ball of five tailed beasts.

Even though it is extremely durable, Kurama, when caught off guard, can be weakened by attacks that deals with massive physical impacts, such as Naruto's senjutsu-enhanced Wind Release: Rasenshuriken and Sage Art: Many Ultra-Big Ball Spiralling Serial Spheres. Kurama will "die" with its jinchūriki, if it is still sealed within them at the time of its host's death. The fox will, however, be revived later. It is also susceptible to control by the Sharingan, though only Madara Uchiha and Tobi had accomplished this great feat. Despite being the strongest of the nine tailed beasts, Kurama acknowledges the fact that it alone wouldn't stand a chance against the Ten-Tails and that there is only a slight possibility of winning if the fox fought alongside with the other tailed beasts.

Activity inside Naruto
As Kurama's jinchūriki, Naruto is gifted with its enormous supply of chakra, to which Kakashi Hatake estimated it to be a hundred times greater than his own when its influence is not suppressed. It also gives Naruto accelerated healing (recovering from minor injuries within seconds and major injuries within a day). Also, depending on the amount of Kurama's chakra he's using, Naruto is given an increase in strength, speed, and his healing factor are pushed to such levels that he completely recovered from a Chidori through his chest in mere seconds with no signs left. At times, he is also granted a fox-shaped chakra shroud with massive invulnerability, being able to resist being pierced by Orochimaru's Sword of Kusanagi, a sword known as being able to cut through adamantine, and is completely undamaged by the alkali substance excreted by Saiken, which was able to damage Gyūki and disintegrate its surroundings rapidly.

Land of Waves Arc
Naruto first made use of Kurama's chakra during his battle with Haku. Believing Haku to have killed Sasuke, Naruto gave into his anger and entered his initial jinchūriki form in order to defeat Haku.

Chūnin Exam Arc
During the second stage of the Chūnin Exams, Kurama's chakra emerged again while Naruto battled with a disguised Orochimaru. However, Orochimaru, knowing that it was Kurama, used the Five Elements Seal to block Naruto's access to Kurama's chakra, rendering the former unconscious.

Naruto did not realise that it was Kurama's chakra until he was later taught to take advantage of it by Jiraiya, who later removed Orochimaru's seal on Naruto. To force Naruto to call upon Kurama's chakra, thus enabling him to use the Summoning Technique, Jiraiya pushed Naruto off of a cliff. In a desperate act to save himself, Naruto suddenly entered his own subconscious and met with Kurama for the first time. Kurama immediately expressed its desire to kill and devour the boy, but Naruto, even though he discovered what he was facing, bravely demanded Kurama to give him some of its chakra as a form of "rent" for being sealed within his body. Realising that Naruto's death would result in its own, the intrigued Kurama complied, giving Naruto enough chakra to summon Gamabunta.

Kurama then kept quiet till Naruto battled Neji Hyūga in the first match of the final round of the Chūnin Exams. After Neji used his Eight Trigrams Sixty-Four Palms to block Naruto's chakra points, Naruto called upon Kurama for assistance. Without hesitation, it gave Naruto enough chakra to force his chakra points to open and defeat Neji.

Invasion of Konoha Arc
During Sunagakure and Otogakure's Invasion of Konoha, Naruto and Gamabunta both did a Combination Transformation technique to take the form of a giant fox (Kurama itself in the anime), to battle against Gaara in his full Shukaku form. As the battle was near to its conclusion, Naruto called upon Kurama again for chakra in order to defeat Gaara, and once again, it did so without hesitation.

Search for Tsunade Arc
While on his search for Tsunade with Jiraiya, Naruto was confronted by Itachi Uchiha and Kisame Hoshigaki of Akatsuki. Naruto tried to use Kurama's chakra to help him fight against them, but Kisame quickly used his Samehada sword to absorb it all and attempted to cut off Naruto's arms. Luckily, Jiraiya arrived in time to block Kisame's attack with his toad summon and was able to force both Akatsuki members to retreat.

Later, before Naruto defeated Kabuto Yakushi with a complete Rasengan, Kabuto severed Naruto's heart muscles, and his neighbouring chakra system, to which Kurama was unable to heal. While Tsunade desperately tried to save Naruto, Kurama noticed that its power was fading as its surroundings grew darker and darker. It, like Naruto, had a near death experience, something it was slow to recognise. Fortunately, Naruto and Kurama were able to survive this encounter through the help of Tsunade and her medical ninjutsu.

Sasuke Retrieval Arc
During the first stage of Naruto's battle with Sasuke at the Valley of the End, Sasuke, in his first level of the Cursed Seal of Heaven, pierced a fatal wound in Naruto's right shoulder with his Chidori. Fortunately, Kurama quickly gave Naruto enough chakra to heal his large wound almost instantly and entered his initial jinchūriki form. However, as the fight continued, Sasuke was able to predict and overcome Naruto's attacks with his then fully matured Sharingan. Kurama condemned the unconscious Naruto for being too weak, and gave him more of its usual chakra to attain the one-tailed form, something Kurama indicated that he should be grateful for.

Land of the Sea Arc
In the anime, Naruto fought against Amachi in the Land of the Sea after he discovered that the scientist became a monster by utilising the same research he used on Isaribi. Naruto was overwhelmed by Amachi's power at first, but as his desire to keep Isaribi from becoming a monster grew, Kurama immediately gave Naruto enough chakra to enter his initial jinchūriki form, and he quickly defeated Amachi.

Kazekage Rescue Arc
During the conclusion of his battle against the Akatsuki member Deidara, which turned out to be a clay clone, Naruto slipped into his two-tailed form out of anger about Gaara's death. Immediately, Kakashi placed Jiraiya's special seal tag on Naruto's forehead, restoring him back to normal.

Sasuke and Sai Arc
When his three-tailed form was proven insufficient in his fight against Orochimaru, Naruto gave into Kurama and entered his four-tailed form. Kurama gained control of his senses and began to attack everything that was around him, including both Orochimaru and Sakura Haruno. After its influence was suppressed by Yamato, he told the nescient Naruto that he was the cause of Sakura's injury, which greatly shocked Naruto and resolved not to rely on Kurama's power again.

Soon afterwards, when Naruto encountered Sasuke again for the first time in almost three years, Kurama began to offer Naruto its chakra, but he firmly rejected its assistance. Kurama became contemptuous at Naruto, mocking him that if it wasn't for its power, he would be nothing. It then tempts Naruto to break the seal so it can "grant" him all of its power, but he still refused. However, before their quarrel could escalate any further, Sasuke, with his active Sharingan, suddenly appeared within Naruto's subconscious, which surprised both Naruto and Kurama. Kurama became impressed with Sasuke's growth and ability, but as it stated that Sasuke's chakra was similar to Madara Uchiha, Sasuke effortlessly suppressed the fox's residual chakra with his Sharingan. Although angrily shocked by the display of his power, Kurama concluded that this might be its last meeting with Sasuke, so it warned him not to kill Naruto, because he would only end up regretting it.

Twelve Guardian Ninja Arc
In the anime, Kurama reacted to its leftover chakra that was stored within Sora. When Naruto in his three-tailed form battled Sora in his four-tailed form, Kurama started to force Naruto to accept its power, but he was able to keep it from taking control of his body as he threatened the fox to back off. Kurama begrudgingly pulled back, but it soon managed to absorb back all of its chakra from Sora.

Hidan and Kakuzu Arc
During Naruto's nature transformation training, Kurama's chakra was surfacing within some of his shadow clones that had grown very frustrated with combining the Rasengan with his wind element. Fortunately, Yamato was able to suppress the chakra before it could cause serious damage.

Invasion of Pain Arc
During Naruto's training at Mount Myōboku, Kurama prevented Fukasaku from fusing with Naruto, making it impossible for him to mould senjutsu chakra for Naruto.

Later, during Naruto's battle with Pain, he slipped into his six-tailed form right after Pain appeared to have killed Hinata Hyūga. Despite the necklace's attempts to suppress it, Kurama quickly seized the necklace and crushed it. When Naruto was soon contained by Pain's Chibaku Tensei technique, Kurama tempted Naruto to entrust his heart to it so that it could destroy everything that was causing Naruto pain, thus distorting the seal to the point where the eight-tailed form was released. Before it could convince him to completely remove the seal, the spirit of Minato appeared in Naruto's subconscious and stopped him. Enraged, Kurama tried to dare Minato to come closer so it could rip him to shreds, but Minato simply ignored it and restored the seal to its original strength.

Confining the Jinchūriki Arc
When Naruto was summoned back to Mount Myōboku, the Great Toad Sage gave Naruto Gerotora, along with the key to the seal. From this, Naruto was on a task to find a way to control Kurama, in order to fight a fated battle with Sasuke.

Later, at a remote island in the Land of Lightning, after Naruto completed the first step at the Falls of Truth, Killer B then lead Naruto to a special room within the secret temple behind the waterfall, where Naruto would fight Kurama. When Naruto entered his subconscious, Kurama expressed surprise as it could no longer sense any hatred within him, and questioned Naruto about where the "real him" was, to which Naruto replied that the real him was right in front of it. After Naruto used the key to completely unlock the seal, Kurama pushed the cage's doors and fired a Tailed Beast Ball at him, but Killer B used the remaining bit of Gyūki's power to contain the attack. While in Sage Mode, Naruto was able to weaken Kurama with the Wind Release: Rasenshuriken and started to drain out its chakra. However, Kurama planted its hatred within its drained chakra, and it suddenly began to consume Naruto, making him lose the control and forcing him out of Sage Mode. Just before Naruto was completely succumbed, his mother Kushina Uzumaki appeared, halted his transformation, and used her chakra chains to subdue Kurama, to which Kurama reacted in anger and shock when it recognised her chakra.

After being comforted by Kushina, Naruto's positive emotions depleted Kurama's hatred within its drained chakra, and he made a large number of shadow clones, forming multiple Rasengan as they charged at Kurama. After Kurama broke most of the chakra chains, Kushina immediately used the last chain that was attached on Kurama's leg to make it trip, giving Naruto's shadow clones enough time to enter Sage Mode and bombard it with the Sage Art: Many Ultra-Big Ball Spiralling Serial Spheres. As Kurama was pushed back from the impact, one of Naruto's shadow clones immediately used the Rasenshuriken to weaken Kurama further and completely separate it from its chakra. When the chakra merged with Naruto, the enraged Kurama attempted to fire a much larger Tailed Beast Ball, but its attack was ultimately dissipated as Naruto used a new, stronger seal to imprison Kurama once again. As Kurama disappeared into the darkness, it told Naruto that it would never forget this defeat.

Shinobi World War Arc
While Naruto and Killer B continued their way to the battlefield, Kurama pulled its jinchūriki into his subconscious, berating him for squandering its chakra. Calling Naruto naive for thinking he could stop the war and bear the hatred by himself, Kurama tried once again to tempt him with power, but to no avail, earning Naruto some recognition. After Kurama reminded Naruto about the day he met Sasuke and how he was consumed by hate even then, it claimed that the boy's attempt to put an end to hatred is futile. In retaliation, Naruto pinned Kurama down with a torii while exclaiming with great confidence that he already planned on how to stop both Sasuke and the war. As Kurama recalled Naruto's growth, it then condescendingly complimented him for finally learning how to stand up for himself before being unnerved by the boy's promise to someday resolve the fox's own malice.

Later, after the reincarnated Madara Uchiha was fighting against one of Naruto's shadow clones and the Fourth Division, he attempted to summon Kurama. Even though the summoning failed, the fox angrily recognised Madara's chakra calling for it and resolved to lend Naruto its chakra. Naruto at first thought that it was going to attempt to take over his body like it used to, but Kurama explained that it would rather help Naruto than be manipulated by Madara again. Kurama then spurred Naruto on as he countered the Uchiha's attack.

As Killer B and the real Naruto were fighting against Tobi and the reincarnated jinchūriki, Kurama proceeded to feign sleep while it purposely stopped consuming Naruto's chakra, deciding to let the young man fight on his own against Son Gokū. Gyūki tried to convince Kurama to continue its much needed support, but the fox replied that it would not cooperate with its jinchūriki as easily as Gyūki does. As Kurama remembered the words that Madara, Hashirama, Mito, and Kushina had said to it in the past, Kurama concluded that no matter how the humans said it, it would always come down to the same thing, with the exception of Naruto, a thought which silenced it. Kurama quietly watched on as Naruto was speaking with Son Gokū, only expressing annoyance when its name was revealed to Naruto.

While thinking back on the events in Naruto's life and watching the proceeds, Kurama silently noted that Naruto of all people should know that no matter what he said to the tailed beasts, his true intentions would only reach them through his own actions. After Naruto successfully removed Tobi's control over Son Gokū, Kurama silently celebrated the small victory and offered to lend him more of its chakra. Before accepting however, Naruto thanked Kurama for its help during his encounter with Madara, to which the fox rebuffed him before offering to meld their chakra together. Accepting this proposal, Naruto opened the seal's gate that held Kurama back and acknowledged it as his team-mate from Konoha. As a result, Kurama enabled Naruto to enter a new form, in order to stop the other tailed beasts that were bearing down on Might Guy and Kakashi.

However, as this was their first time transforming into this mode, Kurama warned Naruto that they only had five minutes. They first started by grabbing Chōmei in mid-flight to pile-drive it into Isobu, but it rolled out of the way to counterattack after Saiken quickly swallowed Kurama's hand prior to Gyūki joining the fray. When Matatabi attempted to pounce on Naruto and Kurama from behind, they fiercely swung Saiken right into the monster cat, throwing the two away from a distance. As the other tailed beasts gathered and preformed a collaborative Tailed Beast Ball, Naruto and Kurama preformed one of their own and cancelled the attack. Right after that, Naruto entered a deeper level of Kurama's subconscious, where he meets the other five tailed beasts and their jinchūriki, to which Kurama explained that this was somewhere not even Tobi could enter. As it remembered the Sage of the Six Paths, Kurama asked its brethren if they too believed that Naruto was the one the Sage had spoken of so long ago, to which they agreed before being resealed into the Demonic Statue of the Outer Path.

While they were fighting against the Demonic Statue of the Outer Path, Tobi summoned both the Benihisago and the Kohaku no Jōhei which contained the reincarnated Gold and Silver Brothers, who possessed a portion of Kurama's chakra. Right after the masked man made the giant statue devour them, Kurama, who had sensed its own chakra signature within those two items, requested Naruto to switch with it so it could explain the situation to the others, as well as about the Ten-Tails and what its revival would mean. Kurama also echoed Kakashi's words that something needed to be done before the Ten-Tails' revival was completed, afterwhich, on Naruto's request, Kurama switched back with him. Kurama was later seen smiling when Naruto opposed Tobi's ideals and told him that he was who he was today because he had heroes to look up to and to show him the way. After a brief fight, Tobi tried to instill doubt into Naruto by telling him what would Jiraiya and Minato say if he ended up neglecting the legacy they left him. Kurama, recalling what Minato said to Naruto during his battle with Nagato, requested Naruto to switch again and directly told Tobi that Naruto would never follow his ideals and that Minato sealed it into Naruto so that he could defeat Tobi. After melding their chakra together once more, Naruto entered his Tailed Beast Mode and Naruto began his assault on Tobi after being assured by Kurama that he would not fail. Later when Tobi tried to hit Naruto with a barrage of shuriken Naruto materialised Kurama's head which in turn caught the shuriken.

Naruto the Movie: Ninja Clash in the Land of Snow
During the fight between Naruto and Dotō Kazahana, he managed to knock Naruto, who was at the disadvantage due to having the Chakra Negator on him, though the ice of the lake they were standing on, causing him to sink beneath the waters. However, as Naruto called upon Kurama for its chakra, which helped break the Chakra Negator, it allowed him to recover quickly and summon his shadow clones to overwhelm Dotō.

Naruto 6: Road to Ninja
In the alternate world that Naruto and Sakura ended up in, Kurama has a counterpart called "Dark Kurama", who is sealed within the body of Naruto's alternate self, Menma. Other than giving its jinchūriki similar benefits like its counterpart does for Naruto, Menma can use the dark fox's chakra to create constructs that wear masks like his own.

Trivia

 * literally means 'nine lama'. Kishimoto was mainly inspired to create Kurama based on the character with the same name from the manga series Yū Yū Hakusho. . The name may also reference, the sacred mountain said to be the home of the Tengu Sōjōbō who taught people ninjutsu and other Japanese martial arts.
 * A is a popular figure in Japanese folklore, and is the influence to many other reincarnations in modern Japanese culture. Kitsune are very well-known to be cunning and mischievous creatures with shape-shifting abilities, to which on occasions, use to transform themselves into beautiful women in order to seduce men (possibly the inspiration for the Sexy Technique). They are also said be rivals to the tanuki, which created an old Japanese proverb:, meaning as much as two sly characters trying to outsmart one another. However, kitsune are known to keep their promises, a trait Naruto has; his ninja way is to "never go back on [his] word". It is also noted that every time Naruto becomes overwhelmed by Kurama's power, he gains another 'tail' of chakra, which stems from the belief that the more tails a kitsune has, the more powerful it is, with nine being the limit.
 * Based on its reaction, Naruto almost dying at the hands of Kabuto was the only time Kurama was close to death, or to that matter, suffered any injury it could not simply heal through.
 * All of Kurama's jinchūriki have come from the Uzumaki clan.

Quotes

 * (To Naruto) "I suppose I can't kill you, can I? After all, you die, I die. Your courage is impressive, little boy… Very well, as a reward for making it this far, I will loan you my chakra!"
 * (To Naruto) "You runt, you really are weak! You better be grateful to me… and to your beloved Fourth Hokage, who sealed me inside a twerp like you!"
 * (To Sasuke) "With that vision of yours and chakra more ominous than my own… You're the spitting image of Madara Uchiha from the elder days…"
 * (To Naruto) "Destroy everything… Erase everything that hurts you… Entrust your heart to me… I will save you from your suffering…"
 * (To Naruto) "You don't have what it takes to control my power! You're nothing more than a mere fragment of my hatred!"
 * (To Naruto) "How stupid are you?! I'm the Nine-Tailed Demon Fox! I haven't fallen so far that a little baby can influence me! I'm a living mass of malevolence!"
 * (To Naruto) "No… I will give you my chakra and it alone! I dislike Madara… if the alternative is being controlled by him… I choose you!"
 * (About humans) "No matter how they say it… humans always say one thing."
 * (About Naruto) "Naruto… If you really want to do something for us… then do what you've always done… Prove it to us with your actions! That's who you are!"
 * (To Tobi) "Sorry but… this guy doesn't suit your words. The Fourth Hokage entrusted me to Naruto… We became friends and now he's able to use my chakra!! The Fourth sealed me into Naruto… to take you down!!"