Ōtsutsuki Clan

The is an ancient clan of horned. After the arrival of one of the clan members on Earth a millennium ago, the Ōtsutsuki began having a lasting influence on the human population, notably starting the history of shinobi.

History
For countless eons, the Ōtsutsuki clan have been travelling throughout dimensions seeking out worlds to plant Ten-Tails into. Once planted, it grows into a God Tree with its roots spreading across the planet to suck chakra from all its inhabitant's lives, resulting in everything dying and it bearing a large fruit for the Ōtsutsuki to consume in order for them to to gain power and prolonged lives. Once harvested, as they no longer need the planet, they move to another to repeat the process. Based on discoveries in an Ōtsutsuki-related site, Sasuke Uchiha postulated they arrived in new worlds in pairs.

The clan sent Kaguya and Isshiki to Earth to collect and prepare its chakra for them. By consuming the planet's Chakra Fruit, Kaguya used the chakra she gained and the Infinite Tsukuyomi to end the constant war of Earth's human population, resulting in world peace and her being initially viewed as a benevolent deity. Foreseeing the consequences of consuming the Chakra fruit against her clan's wishes, she converted the imprisoned Infinite Tsukuyomi victims into a White Zetsu Army in preparation for the arrival of other clansmen looking to steal her chakra; an act which lead to humans viewing her as a demon instead. Meanwhile, Isshiki's fate became largely unknown during those events, but his chakra survived in Jigen, leader of the mysterious organization Kara, and his future successor Kawaki in the form of Kāma.

In time, Kaguya gave birth to twin sons: Hagoromo and Hamura, both of whom were born with chakra of their own. Kaguya grew jealous that they inherited some of her power and so merged with the Earth's God Tree to try and take it back, in the process becoming a monster called the Ten-Tails. The beast terrorised the world until Hagoromo and Hamura defeated it with their Six Paths — Chibaku Tensei, thus creating the Moon. The Ten-Tails' chakra was sealed into Hagoromo while its husk, the Demonic Statue of the Outer Path, was hidden away and sealed on the Moon, in order to prevent the Ten-Tails' revival. Before being sealed, Kaguya sent a manifestation of her will, Black Zetsu to find a way to revive her. Leaving leadership of the clan to Hamura, he decreed that the clan would stand guard over the Demonic Statue. Hagoromo and his brother's direct bloodline stayed on Earth, the latter which inherited the Byakugan and became the Hyūga clan, while Hamura immigrated the clan to the moon, maintaining order and stability with the power of his Tenseigan.

Believing chakra was a power that linked everything in the world, Hagoromo set out to spread the message to the people of the land, during which his teachings became known as ninshū. Towards the end of his life, he divided his chakra into the nine tailed beasts, his way of ensuring that the Ten-Tails and thus Kaguya would never be reborn. Before he died, he passed over his eldest son, Indra, and entrusted his mission of peace to his youngest son, Asura. Black Zetsu manipulated Indra's jealousy toward Asura, resulting in the two brothers' confrontation being passed on to their decendants by the pair being reincarnated. Having spent the remainder of his life overlooking Earth, Hamura entrusted his Ōtsutsuki clansmen with a celestial degree watching over humanity before his passing. Afterwards, the people of the moon treated Hamura's Tenseigan as a treasure, enshrining it as a religious object and devoting a plan to eternally preserving it with the Byakugan of newborn members taken and put into the vessel to power it.

The millennium that passed involved the Moon's branch family misinterpreting Hamura's celestial decree, leading to them believing he wanted his descendants to destroy Earth in the event the world Hagoromo fashioned lead astray. The main family warred against the branch family over their different interpretations and eventually annihilated the former using the weaponized Tenseigan. On Earth, humans along with Ōtsutsuki's descendants such as the Senju, Uzumaki, Uchiha, and Kaguya clan utilised Indra's invention of ninjutsu to shape the shinobi world.

A thousand years after the Ten-Tails' defeat, the Moon's branch family dwindled to only Toneri, who was aware that the Demonic Statue was stolen and the Ten-Tails was revived during the Fourth Shinobi World War. The event ultimately lead to Kaguya being temporarily revived, but was soon sealed along with Black Zetsu in another dimension by the reincarnations of Asura and Indra. Two years later, as his clan had concluded that Earth's shinobi will destroy the world's peace and order, he deemed Hagoromo's world a failure, and began to act on Hamura's mistranslated celestial decree. Unable to reach an agreement with the Hyūga Clan, Toneri resorted to kidnapping the clan's heir and taking her Byakugan in order to awaken the Tenseigan. The act caught the attention of Konohagakure, leading to a team discovering his intentions and defeating him. After becoming aware of Hamura's true decree, he vowed to remain in self-imposed exile on the Moon in order to stand vigil over the Earth as a solitary guardian.

Years later during the Seventh Hokage's era, Momoshiki and Kinshiki in another world became aware of abnormalities in Kaguya's world, prompting them to inform their clan and investigate the situation. Though they weren't aware of the fate of Kaguya or her chakra, by Urashiki's account they saw everything including the Byakugan Princess incident on the Moon. They deemed Kaguya a disgrace and traitor for growing an attachment to Earth and taking up arms against them. By the time Momoshiki and Kinshiki were defeated, Konoha had discovered four separate Ōtsutsuki clan ruins during their investigation of the clan. Sometime afterwards, Konoha had discovered the clan's time-traveling artifact Karasuki, which Urashiki took in a final bid at stealing the Nine Tails' chakra from the past, only for him to meet his end.

In the meanwhile, Jigen as Isshiki's vessel managed to asquire a juvenile Ten-Tails, planning to use it together with Kara as a seed for the new God Tree on Earth. The exact details of their plans remain unknown, but it seems that Kawaki, a new vessel for Isshiki, is crucial for their execution. There was some kind of time limit to their plans, but it was extended to an undefinite amount when Kara discovered that Momoshiki also created a vessel of his own, Boruto Uzumaki, before dying.

Appearance
Members of the original clan's main family all possess pale white skin, blank white/lavender pupilless eyes, either pale blue or white hair, eyebrows shaved into a circular pattern as a sign for nobility, and most notably; various types of brown protrusions from their heads resembling horns. Their biology is close enough to humans to be able to procreate with them, and half human hybrids have similar horn like protrusions, however they are less pronounced and generally appear to be the same colour as their skin.

Abilities
All Ōtsutsuki have possessed at least one inborn skill, the Byakugan being the most prevalent with the potential of awakening the Tenseigan; Kaguya has the Rinne Sharingan and a predecessor ability of the Shikotsumyaku; Hagoromo and Momoshiki both have the Rinnegan, the former of which, in the anime, awakened it after manifesting the Sharingan and Mangekyō Sharingan. Another ability in the anime was the Wood Release as seen by Asura.

Momoshiki claims that the Ōtsutsuki's greatest skill is their ability to use chakra, gaining strength, retain youth, and long life by ingesting it. Indeed, during the Fourth Shinobi World War, those with the Ten-Tails' chakra and even Kaguya herself are impervious to almost every shinobi skill and it is only by using Hagoromo's Six Paths chakra that she is ultimately defeated. Ōtsutsuki seem to remain unprecedentedly resilient even after they die: Hagoromo's soul lives on through his chakra, which itself travels through time so that he might help solve some of the issues that lingered after his death; Hamura's soul manifests before Hinata Hyūga for a similar purpose, giving her the means of stopping Toneri; Indra and Asura's chakra are repeatedly reborn in their descendants so that they can try to settle their age-old competition; Momoshiki's spirit remained intact for a while even after his body was destroyed and was able to say his last words to Boruto.

Ōtsutsuki's resilience is extended furter through the Kāma seal. It is bestowed by a member of the clan on the verge of their death to whoever has defeated them. As a result, the person becomes the Ōtsutsuki's, preserving their chakra and will within the seal. Kāma grants its recipient chakra absorbing abilities and other unique skills of the Ōtsutsuki, and also allows the deceased clan member to manifest their will within the vessel's body. An incompatible body would not be able to handle the Ōtsutsuki's power for very long, but in case of a "perfect" vessel, the progress of Kāma will eventually transform the wielder into a new Ōtsutsuki, effectively serving as a resurrection means.

An ability of the Ōtsutsuki is to move through dimensions, though it requires an enormous amount of energy. They were able to colonise the Moon by creating the Tenseigan, which they further strengthened over the centuries by storing their Byakugan within it. From the Tenseigan they receive light, a habitable environment for themselves and other flora and fauna, power for their equipment, and the ability to control the Moon's movements. They can also use the Tenseigan to remotely control their automatons, a far more advanced precursor of the shinobi's Puppet Technique. When they were alive, Hagoromo and Hamura each used different seals to grant or restrict chakra, some of which persist or are rediscovered long after their deaths.

Trivia

 * roughly means "big bamboo tree" and is derived from an obscure passage in the second volume of the Kojiki about the genealogies of Emperor Suinin, eleventh emperor of Japan, which states that he had a consort named, the daughter of a king named ; tradition holds that these individuals served as the basis for Princess Kaguya and the old bamboo cutter in The Tale of the Bamboo Cutter.
 * The horns sported by members of the Ōtsutsuki clan are meant to symbolise rabbit ears, denoting a connection to the moon by evoking the moon rabbit, with Kaguya even being known as the to her followers. The trend continued with Momoshiki and Kinshiki via their chakra pills, based on the cinnabar elixir that the moon rabbit is depicted using a mortar and pestle to create in Chinese folklore.
 * During the clan's civil war, the main and branch families used different emblems to set each other apart: the main family used an eight-pointed sun ray, while the branch family used a combination of the Six Paths Yin and Yang symbols, a crescent moon and a sun.
 * The Ōtsutsuki clansmen on the Moon donned ceremonial kimonos (with various decorations from the back) with sash tied over the right shoulder and shinobi sandals. In battle, they donned a turban, a mask over the lower-half of their face, a white vest, purple sash, purple pants and a purple long-sleeve shirt with bandages over their arms and feet, and additionally using long robes for commander level.
 * Hinata is referred to by the entire clan as the . The reason for the title is not explained, but by having it, Hinata is immune to Toneri's chakra drain and she is the only individual who can destroy the Tenseigan.
 * The clothes Toneri and Hinata wore during their wedding ceremony were traditional wedding attires of the clan.
 * Passing bread from a groom's mouth to his bride's mouth is part of the clan's wedding ritual.
 * Momoshiki claimed that the transferal of power is the law of the Ōtsutsuki clan, enforcing his act of killing Kinshiki to strengthen himself.
 * In the anime, after Urashiki was killed by Boruto and Naruto, he apparently had not chosen either of them to be a vessel of his chakra through the Kāma.