Yin–Yang Release

techniques make simultaneous use of Yin Release and Yang Release. Yin relates to one's spiritual energy and Yang relates to one's physical energy, and it's necessary to utilise both of these in order to mould chakra for ninjutsu. As such, the basis of simply kneading chakra and using techniques is based in Yin-Yang Release. Furthermore, Yin–Yang Release is suggested to be connected to Six Paths, a term used throughout the Naruto storyline.

Hagoromo Ōtsutsuki, also known as the Sage of Six Paths, had such a mastery over the Yin–Yang Release that he used Yin to create form from nothing, and then used Yang to breath life into what he had created. According to Tobi, this technique was called Creation of All Things Technique, which he employed to create the tailed beasts out of the chakra from the Ten-Tails. The technique Izanagi is said to be based on this technique.

After receiving power from Hagoromo, Naruto Uzumaki gained the ability to use Yin–Yang Release to stabilise life forces and restore missing organs through physical contact. However, there appears to be a limit to the extent to what this power can heal: While he was able to save Might Guy from the normally fatal consequences of unleashing all Eight Gates, he was unable to repair the damage done to his leg as a result of using Night Guy, and Guy spent the remainder of his life wheelchair-bound. Naruto was also able to resuscitate Obito after the Ten-Tails was extracted from him, but both were aware that his death was unavoidable when he was struck by Kaguya Ōtsutsuki's All-Killing Ash Bones.

As Tobirama Senju noted, Yin–Yang Release also has the ability to nullify the effects of all ninjutsu, rendering them useless. Obito and Madara Uchiha demonstrated this through their usage of the Truth-Seeking Balls. As Sasuke Uchiha noted, combining his Six Paths Yin Power and Naruto's Six Paths Yang Power, which was acquired via Hagoromo granting them his chakra, was the only possible method to seal a being as powerful as Kaguya, the progenitor of chakra itself.

Trivia

 * In chapter 606, when Madara speaks to Obito about the techniques he will teach him, the Kanji for Yin–Yang are read as "In'yō". In the real world, this is the common reading of 陰陽, whereas the Naruto manga normally uses "Onmyō".
 * In chapter 684, Black Zetsu uses the same reading to refer to Naruto's and Sasuke's.