Nature Transformation

is an advanced form of chakra control that entails the moulding and defining of one's chakra into an innate kind of chakra nature, altering its properties and characteristics for use in techniques. Nature transformation is one of two necessary components for creating or modifying a technique, the second component being shape transformation. While nature transformation changes the nature of the chakra, shape transformation changes the actual form and movement, altering its abilities.

Basic Nature Transformations
The are the most fundamental chakra natures, which are the foundation of all elemental ninjutsu. They are so vital to the shinobi lifestyle that each of the Five Great Shinobi Countries is named after one of the five. Each nature is naturally weaker than one nature and stronger than another:
 * is strong against Wind but weak against Water.
 * is strong against Lightning but weak against Fire.
 * is strong against Earth but weak against Wind.
 * is strong against Water but weak against Lightning.
 * is strong against Fire but weak against Earth.

Basically, if an elemental technique is put against another elemental technique of the same level, but of a stronger nature, then the technique with the superior nature will prevail. However, a technique with a weaker nature can overpower a technique with a stronger nature if the former is of a higher level. For example, fire can overpower a water technique if it is first strengthened by a wind technique.

A similar principle applies in how technique of the same element interact, what is called. If two techniques of the same nature and the same level are used against each other, they will cancel each other out, as when Lightning Release: False Darkness is deflected with Lightning Cutter. However, if the two techniques have different levels, the higher-level technique will not only prevail but will grow stronger from interaction with the weaker, as when Amaterasu (the highest level Fire Release technique) grew stronger by absorbing an opposing Fire Release: Great Fireball Technique.

Affinity
In general, every person's chakra has an affinity towards one of the five basic nature transformations. Affinity can at times be genetic, or at least common to a particular family; most members of the Uchiha clan have an affinity towards the Fire nature. One's affinity can be determined using pieces of paper made from a special type of tree that is grown and fed with chakra: when the paper is exposed to even the slightest hint of chakra, it will react according to the chakra's latent nature:
 * Fire: the paper will ignite and turn to ash.
 * Wind: the paper will split in two.
 * Lightning: the paper will wrinkle.
 * Earth: the paper will turn to dirt and crumble away.
 * Water: the paper will become wet/damp.

Shinobi have an easier time learning to create and control chakra natures that match their affinity, although even then it may take any number of years. Shinobi are not limited to the nature they have an affinity for, and it is in fact common for jōnin to have mastered two natures. Although it is technically possible to master all five natures, it is very rare because of how much of training is involved; Madara Uchiha, Hiruzen Sarutobi, Hashirama Senju, Tobirama Senju, Mū, Kakashi Hatake, and Orochimaru are the only shinobi known to have done so via normal means. Other methods of acquiring all five natures include:
 * Possession of the Rinnegan.
 * Usage of Six Paths Senjutsu
 * Usage of the Truth-Seeking Balls.
 * Using Earth Grudge Fear to gather hearts with other chakra natures.
 * In the anime, Fūka got them by stealing others' chakra, though due to the accumulated amounts surpassing one body's limits, she had to divide them in various combinations in multiple bodies.
 * In Naruto Shippūden the Movie: The Will of Fire, it was stated one who absorbs five kekkei genkai with the Chimera Technique would gain a mastery over all five natures.
 * In Naruto Shippūden: Dragon Blade Chronicles, Naruto gets the Dragon Blade, which allows him to use all five natures.

Combined Nature Transformations
By using two or three basic natures simultaneously, one can create a completely new nature with unique properties that wouldn't exist on its own. However, doing this requires a kekkei genkai or, if three natures are used, a kekkei tōta. In the anime, it is further stated that those with the ability to combine the elemental nature transformations possess an affinity for the chakra natures they must simultaneously use.

In the manga, nine combined nature transformations have been shown:
 * is created by simultaneously combining the Water and Wind natures. Infamously used by the Yuki clan, their kekkei genkai.
 * In Naruto the Movie: Ninja Clash in the Land of Snow, Yukigakure-nin were able to use a different kind of Ice Release by drawing on already-existing ice, snow, and cold. This was not a kekkei genkai, as Kakashi could copy one of these techniques with his Sharingan.
 * is created by simultaneously combining the Earth and Water natures. Famed as the kekkei genkai of Hashirama Senju, and thus reproduced in those using his cells.
 * is created by simultaneously combining the Fire and Earth natures. A characteristic of the Four-Tails and its jinchūriki, and a kekkei genkai used by ninja of Kirigakure, Iwagakure, and Kumogakure. Also used by ninja of Amegakure in the anime and Ishigakure in the novels.
 * It is implied that the two ways of writing this nature (熔遁; 溶遁) are pointing out that they are different in some way. They are switched around and alternated throughout the plot, with Iwa and Kumo characters using the kanji "熔" and the Kiri characters using the kanji "溶". However, the true purpose of this difference is unknown.
 * is created by simultaneously combining the Lightning and Water natures. A kekkei genkai used by Darui and many other unnamed Kumogakure ninja.
 * In Naruto Shippūden the Movie: The Will of Fire, the ability to use Storm Release is stolen by Hiruko from an unnamed shinobi. This version has significant differences from those used elsewhere in the series.
 * is created by simultaneously combining the Water and Fire natures. A characteristic of the Five-Tails and its jinchūriki, and one of the kekkei genkai used by the Fifth Mizukage.
 * is created by simultaneously combining the Fire, Earth, and Wind natures. A kekkei tōta used by the Second and Third Tsuchikage.
 * is hinted to be made of the Earth and Lightning natures. A kekkei genkai common to members of Iwagakure's Explosion Corps.
 * is implied to be created by simultaneously combining the Fire and Wind natures. A kekkei genkai only known to be used by Pakura.
 * is implied to be created by simultaneously combining the Wind and Earth natures. A characteristic of the One-Tail and its jinchūriki, and one of the kekkei genkai used by ninja of Sunagakure and Kumogakure. In the novels, it is also used by ninja of Ishigakure.

In the anime, novels, and movies, four additional chakra nature transformations have been shown:
 * Used in the anime, is suggested to be made of at least the Earth nature. Used by Guren.
 * Used in Gaara Hiden and Naruto Shippūden the Movie: The Will of Fire, is a kekkei genkai used by Metoro Konjiki and stolen from an unnamed shinobi by Hiruko.
 * Used in Naruto Shippūden the Movie: The Will of Fire, is a kekkei genkai stolen by Hiruko.
 * Used in Naruto Shippūden the Movie: The Will of Fire, is a kekkei genkai stolen by Hiruko.

Yin and Yang
Aside from the five elemental nature transformations, there is a second set of "natures" that are the source of all non-elemental techniques such as the Shadow Imitation Technique, Multi-Size Technique, medical ninjutsu, genjutsu, etc. There is, the basis of imagination and spiritual energy, and , the basis of vitality and physical energy. Together, they are used to perform.

The transformation of the Yin and Yang seemingly has to do with altering the 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.

Trivia

 * The concept of nature transformation parallels the real-life art,, which is a mixture of natural sciences and occultism. It largely features Wu Xing and Yin and Yang.
 * Techniques such as the Toad Oil Bullet and the Poison Mist mention "converting" or "kneading" chakra into materials or substances, but have never been mentioned to use certain chakra natures.
 * Certain other techniques involved in manipulating substances are also often confused to be chakra natures, such as silk, bone, and ink. However, these substances cannot be produced from chakra alone, meaning the chakra is not changed in nature, and it is rather used to change already-existing substances.
 * In Naruto: Shippūden episode 63, Yamato incorrectly says that no known shinobi has ever mastered all five nature transformations.
 * In Naruto episode 174, Kunihisa used "techniques" he called which was used to simply buy whatever he wanted.
 * The Yata Mirror was said to be imbued with all nature transformations to change its own characteristics to deflect any attack. Whether this means it contains combination nature transformations is unknown.