Yin–Yang Release

Aside from the five basic types of nature transformation, there is also a sixth type: the chakra, the basis of "imagination and spiritual energy", and the  chakra, the basis of "vitality and physical energy", thus the Yin and Yang Release. Yamato implied that the Yin and Yang are the source of non-elemental jutsu such as Shadow Imitation Technique, Multi-Size Technique, medical ninjutsu, genjutsu, etc.

The transformation of the Yin and Yang 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 she was the same type of ninja as he is, being able to use such kinds of "special chakra" in battle, supporting the belief that his clan's shadow-based jutsu such as the Shadow Imitation Technique is also Yin and Yang-based.

When Minato Namikaze sealed the Nine-Tailed Demon Fox within his son, Naruto Uzumaki, he split its chakra into a Yin and a Yang, sealing the Yang half within Naruto, and the Yin half within the Dead Demon Consuming Seal. This explains why, when Naruto transformed into his controlled jinchūriki form, Yamato's Wood Release totems reacted to the Yang chakra's life-giving nature, and they transformed into full grown trees.

According to Madara Uchiha, the Sage of the Six Paths could use the power of Yin to give shape and form out of nothingness, and use the power of Yang to breathe life into anything he wished. It enabled him to create anything, dimming the line between imagination and reality. The prime example of this power was the creation of the tailed beasts.