Kurama

, better known as the is the tailed beast sealed within Naruto Uzumaki of Konohagakure and was previously sealed within Kushina Uzumaki and Mito Uzumaki before her.

Background
According to Tobi, Kurama first came into being in the waning days of the Sage of the Six Paths life; to prevent the Ten-Tails resurgence, the Sage split up its chakra and used his ability to create nine separate, monstrous constructs of living chakra, which would become known as the tailed beasts. Over the centuries, Kurama had gained a reputation as an age-old natural disaster, appearing suddenly out of nowhere to attack areas wherever human malice had collected and festered.

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 it swallowed them whole. However, the two brothers managed to survive and gain some of its chakra and 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 Eternal Mangekyō 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 that it tore the earth's surface apart and created the Valley of the End. Despite being in control of Kurama, Madara was defeated and was believed to have died. After the battle, Hashirama's wife, Mito of the Uzumaki clan, sealed Kurama within herself in order to keep the threat that it posed contained, becoming its first jinchūriki. 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.

Twelve years before the start of the series, after the end of the Third Shinobi World War, the seal containing Kurama within Kushina weakened as she became pregnant and gave birth to Naruto. Despite keeping her childbirth a secret, Tobi discovered their location, killed their escorts, broke the seal, and seized control of Kurama. Since Kushina survived the extraction, Tobi tried to have Kurama kill her, but Minato arrived in time to save Kushina and brought her to safety with Naruto. After that, Tobi summoned Kurama into Konoha, and ordered it to destroy the village.

While Kurama went on a rampage in the village, it sensed Minato's presence and quickly fired a Tailed Beast Ball at him, but Minato was able to teleport the attack to a far off location. Kurama was eventually released from Tobi's control when Minato placed a Contract Seal on Tobi, but not before it had decimated the shinobi forces that attempted to repel it. Before Kurama could annihilate Konoha, Minato summoned Gamabunta on top of the beast, 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 the beast, 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, before preparing the Eight Trigrams Seal to imprison the beast, along with its Yang chakra, within Naruto. Kurama realised Minato's intention and took the chance to attack Naruto when Kushina was weakened, but its attack was unsuccessful as both Minato and Kushina quickly used their own bodies to shield their child, piercing them instead of Naruto. Before the sealing was complete, Kurama used its last moment of freedom to curse the pair.

For the past twelve years without Naruto's knowledge of its presence within him, Kurama had been silently watching over Naruto.

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.

Kuruma is bullsshitting oversized fox SNM

Appearance
Although Kurama primarily resembles a kitsune with red-orange fur and blood-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 its attack on Konoha, Kurama was shown to be around the same size as the Hokage Monument, and then 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 former look after it had been consuming Naruto's chakra while he was using its chakra.

Abilities
Being the strongest of the nine tailed beasts, Kurama is said that it 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 shock wave that can repel and destroy anything within its radius, increase its physical strength and speed, and fire Tailed Beast Balls. In the anime, it was shown to be able to create twisters and breathe fire.

During its battle with Naruto in his subconscious, it was shown that even though it had its Yin chakra sealed away, Kurama was more than powerful enough to overwhelm the Eight-Tails' attempts to restrain it (although Killer B stated that he didn't have full access to his own powers within Naruto's mind), and effortlessly block Naruto's Sage Art: Ultra-Big Ball Rasengan with its tails. Naruto also noted that it was extremely fast despite its massive size. Later, even after most of its chakra was taken by Naruto, it still had enough to create a Tailed Beast Ball many times its own size. If its jinchūriki dies (causing Kurama to die with them), Kurama will later revive.

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. It is also susceptible to control by the Sharingan, though only Madara Uchiha and Tobi had accomplish this great feat. Sasuke Uchiha had also used his Sharingan on Kurama, but only to suppress a small amount of its chakra.

After Naruto conquered his dark side, it was revealed that Kurama also has the ability to sense negative emotions, after it inquired about the "real Naruto". Naruto also gained access to this ability after gaining control of its chakra.

Activity inside Naruto
As Kurama's jinchūriki, Naruto is gifted with its enormous supply of chakra and stamina, 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 a few seconds to major injuries within a day), and depending on the amount of Kurama's chakra he's using, Naruto is also given an increase in strength, speed, and his healing factor to such levels that he recovered from a Chidori strike through his chest in mere seconds. At times, he is also granted a nearly impenetrable, fox-shaped chakra shroud.

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 Orochimaru. However, Orochimaru, knowing that it was the Kurama, used the Five Elements Seal to seal off Naruto's access to the Kurama's chakra, rendering the former unconscious.

Naruto did not realise that 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 the 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 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", in order to save themselves. Realising that the situation was taking on a life-or-death matter, 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, through him, Kurama, were saved by Tsunade.

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 tried to tempt 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 Sharingan activated, suddenly appeared within Naruto's subconscious, which surprised both Naruto and Kurama. Kurama became impressed with Sasuke's growth and ability, but as it criticised that he was similar to Madara Uchiha, Sasuke coldly reacted by using his Sharingan to suppress Kurama back into its cage, to which it never thought that he was quite capable of that feat. Kurama concluded that this was probably its last meeting with Sasuke, so it warned him not to kill Naruto, for 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 beast 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, wanting Naruto to use its chakra instead of senjutsu chakra. It was later given an opportunity to appear during Naruto's battle with Pain. After Pain appeared to have killed Hinata Hyūga, Naruto slipped into his six-tailed form. Despite the necklace's attempts to suppress it, Kurama quickly seized the necklace and ultimately crushed it.

When Naruto was contained by Pain's Chibaku Tensei technique, Kurama tempted Naruto to entrust his soul 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.

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 the Eight-Tails' power to contain the attack. While in Sage Mode, Naruto had one of his three shadow clones perform the Sage Art: Ultra-Big Ball Rasengan on Kurama as a distraction for him to come from behind, slam it to the ground, and had his two other shadow clones attack it from above with the Wind Release: Rasenshuriken, causing great damage and giving Naruto the chance 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 the 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 Tailed Beast Ball, but its attack was ultimately dissipated as Naruto used a new, stronger seal to imprison Kurama once again. 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 Naruto into his subconscious, berating him for using its chakra so carelessly. 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 taunted Naruto about his inability to erase the hatred from others and the world. In retaliation, Naruto pinned Kurama down with a torii and told the beast with great confidence, that he planned to do something about 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. Naruto, unnerving Kurama with his trademark smile, said that maybe someday he would do something about its hatred as well. Kurama reproached him for believing that, but Naruto, determined as ever, vowed to Kurama that it would be worth a shot as he left, leaving Kurama speechless.

Later, after the resurrected 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 beast angrily recognised his chakra just as soon as it sensed it. As Kurama resolved to lend Naruto its chakra, he first thought that it was going to attempt to take over his body like it used to, but the beast said it would rather help Naruto than be manipulated by Madara again. It spurred him on as he countered Madara's attack.

During Naruto's conversation with Tobi, Kurama looked seemingly shocked after hearing Naruto state that it was not all bad having to live with a tailed beast sealed inside of him. As the battle with Tobi and the resurrected jinchūriki raged on, the Eight-Tails stated that seeing tailed beasts treated like tools naturally irritated other tailed beasts, but Kurama retorted that every shinobi except B had always treated them as pets. The Eight-Tails claimed that it knew what was going on with Kurama, but before it could say anything, it was angrily interrupted by Kurama telling the Eight-Tails to hurry up and end the battle as it proceeded to feign sleep. When Naruto was injured and fell out of Nine-Tails Chakra Mode, the Eight-Tails noticed that Naruto wasn't in critical condition after using too much of Kurama's chakra, mainly because Kurama had purposely stopped consuming Naruto's chakra a while ago. Remembering Naruto's words, Kurama peered with one eye as Naruto regained his chakra shroud before he stopped himself from being swallowed by Son Goku.

The Eight-Tails told Kurama that its help would be appreciated at the moment, but Kurama replied that it would not bow to the will of its jinchūriki as easily as the Eight-Tails does, causing the Eight-Tails to question whether Kurama cared about what happened to Naruto at all. As Kurama remembered the words that Madara, Hashirama, Mito, and Kushina had said to it, Kurama concluded that no matter how the shinobi said it, it would always come down to the same thing. It watched on as Naruto spoke with Son Goku.

Influence
A is a well-known character in Japanese folklore, and is the influence behind not only Kurama, but many other reincarnations in modern Japanese culture. Kitsune are cunning and mischievous creatures, as they like to play pranks on people, and, on occasions, transform themselves into a beautiful woman in order to seduce men (possibly the inspiration for the Sexy Technique). 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 loses control and is overwhelmed by Kurama's chakra, he gains another 'tail' of chakra. This stems from the belief that the more tails a kitsune has, the more powerful it is, with nine being the limit.

Trivia

 * 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 the jinchūriki of Kurama have been from the Uzumaki clan.
 * According to the second artbook, Kishimoto was mainly inspired to create Kurama after reading the manga series Yu Yu Hakusho. This could mean that the beast was inspired by Yoko Kurama with whom the beast shares the same name.

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 Naruto) "Now then… Who do you want to kill…?"
 * (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 Sasuke) "I never thought that you are able to suppress my power!… This may be our last meeting, but I warn you… Don't kill Naruto… You will only… end up… regretting it…"
 * (To Naruto) "Destroy everything… Erase everything that hurts you… Entrust your heart to me… I will save you from your suffering…"
 * (To Naruto) "You even joined forces with the Eight-Tails… and you call yourself a jinchūriki!? You should be ashamed!"
 * (To Naruto) "You don't have what it takes to control me! You're nothing more than a mere fragment of my hatred!"
 * (To Naruto, after it’s been resealed) "I won't forget this… Naruto…"
 * (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!"