Board Thread:General Discussion/@comment-1875854-20150221232630/@comment-4961229-20150227233440

Naruto Databook 4: Ying Yang/Onmyouton page:

Inton (Yin/Dark), which creates form from nothing, and Youton (Yang/Light), which breathes life into form. Skillfully manipulating these two elements, the Sage of Six Paths, Ootsutsuki Hagoromo, developed the Banbutsu Souzou (Creation of All Things) Jutsu. Creating the nine Bijuu out of the Juubi's chakra was also the result of Onmyouton. Afterwards, Inton was inherited more predominately in the Uchiha clan, while Youton was inherited more predominately in the Senju clan.

Then, can only the Uchiha and Senju use this power? The answer is no. For example, even without using a Sharingan, the proportional amount of genjutsu that involves "creating form from nothing" is high. Furthermore, there are many "hiden ninjutsu" passed down among specific shinobi clans that are not affiliated with any of the five nature transformations but are instead grounded in Onmyouton. For example, the Akimichi clan uses Youton to expand their bodies' size, while the Nara clan uses Inton to expand, contract, and transform shadows. In the same vein, even without being Uchiha or Senju, shinobi manipulate chakra and use jutsu, and the basis of that is said to be rooted in Onmyouton.

Translation by Geg from NF