Nataku is a supporting character in the series X, appearing as a member of the Dragons of Earth. This being is an androgynous clone created from the genetic material of Kazuki Tojo, the deceased granddaughter of the president of the Tojo Pharmaceuticals corporation, and her father Masaki. As a result, Nataku possesses extreme psychic ability. The clone is initially dispatched by the Chairman of Tojo Pharmaceuticals to steal the Shinken, a sacred sword kept at the Monou family temple. The Chairman hopes to destroy the sword so that Nataku will not become entangled in the conflict of the Promised Day. During the theft, Nataku mortally wounds Kyogo Monou, the father of Fuma and Kotori, who was trying to protect the blade.

Nataku is haunted by the lingering memories of its previous life as Kazuki. This emotional residue drives the clone to follow Fuma Monou unquestioningly, because Fuma physically resembles the person Kazuki cared for most: her father. This devotion largely defines Nataku’s motivations during the story. Through encounters and battles with the Dragon of Heaven Karen Kasumi, Nataku gradually begins to understand and experience emotions, marking a key character development. Despite its immense psychic powers and role as a Dragon of Earth, Nataku is portrayed as a tragic figure struggling with identity and attachment.

Notable abilities include telekinesis and the power to manipulate fabric, which it uses both offensively and to bind or imprison opponents. In later alternate continuity, such as the Tsubasa Reservoir Chronicle series, Nataku appears as a mentally developed adult who cares for an alternate version of Kazuki.