Aside from the five basic types of nature transformation, there is also a sixth type: the Yin (陰, In), the basis of imagination and spiritual energy, used to perform Yin Release (陰遁, Inton); and the Yang (陽, Yō), the basis of vitality and physical energy, used to perform Yang Release (陽遁, Yōton). Together, they are used to perform Yin–Yang Release (陰陽遁, Onmyōton). Yamato implied that the Yin and Yang are the source of non-elemental techniques such as the Shadow Imitation Technique, Multi-Size Technique, medical ninjutsu, genjutsu, etc.
The transformation of the Yin and Yang seemingly has to do with altering the amounts of and balance between spiritual and physical energy in chakra. As explained by Shikamaru Nara, Tayuya's spirit worms were forms of spiritual energy that have small amounts of physical energy, thus they require stability and feed upon the physical energy they lack. Shikamaru also mentioned that Tayuya was the same type of ninja as he is, being able to use such kinds of "special chakra" in battle, supporting the belief that the Nara clan's shadow-based techniques are also Yin and Yang-based.