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 cultivated with the God Tree. Once they find such a world, they harvest the god trees' fruit so that they can use its chakra to gain power and prolong their lives. In the case of Momoshiki, Kinshiki, and their ancestors, they would remain on a world until the God Tree was dead and the world could no longer support life, at which point they would seek out a new one. Based on discoveries in an Ōtsutsuki-related site, Sasuke Uchiha postulated they arrived in new worlds in pairs.

At the time Kaguya was the clan's leader, she arrived on Earth with the clan. Eating 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 viewed as a benevolent deity. Foreseeing clan members coming to Earth to steal her chakra, she converted the imprisoned Infinite Tsukuyomi victims into a White Zetsu Army in preparation for their arrival. The act lead to humans viewing her as a demon. The Ōtsutsuki clan, having sent Kaguya to collect and prepare the chakra for them, deemed her a traitor for growing an attachment for Earth and preparing an army against them.

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. Leaving leadership of the clan to Hamura, he decreed that the clan would stand guard over the Demonic Statue. Immigrating the clan to the moon, his direct bloodline and Hagoromo stayed on Earth, the former which inherited the Byakugan and became the Hyūga clan. The Moon settlement would go on to implement the custom of newborn members having their Byakugan taken and put into the Tenseigan to power it, which Hamura used to bring order and stability to the world of the Moon.

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. Having spent the remainder of his life overlooking Earth, Hamura entrusted his fellow Ōtsutsuki with watching over humanity before passing away. Afterwards, the people of the moon treated Hamura's Tenseigan as a treasure, leading to them enshrining it as a religious object and devoting a plan to eternally preserving 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 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 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. During Konoha's investigation of Kaguya, they had discovered four separate Ōtsutsuki clan ruins. Momoshiki thought of Kaguya's defeat as saving him from needing to punish her himself for betraying the clan; he even condemned her as a disgrace to the clan.

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 even after his body was destroyed and was able to say his last words to Boruto, as well as leave a mark on his palm.

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.
 * Momoshiki claimed that anyone who defeated a god (i.e. the Ōtsutsuki clansmen) cannot remain as an ordinary human any longer. Koji Kashin later enforces this by expressing the notion that Boruto having the Kāma is proof that he was the one who defeated Momoshiki.
 * It appears this only applies to actually killing an Ōtsutsuki, as neither Naruto, Sasuke nor Hinata received the Kāma for sealing Kaguya or simply defeating Toneri without killing him.