Chakra (チャクラ, chakura) is essential to even the most basic technique; it is the moulding of the physical energy (身体エネルギー, shintai enerugī) present in every cell of the body and the spiritual energy (精神エネルギー, seishin enerugī) gained from exercise and experience. Once moulded, it can be channelled through the chakra circulatory system, which is to chakra as the regular circulatory system is to blood, to any of the 361 chakra points (called tenketsu) in the body. Through various methods, the most common of which is hand seals, the chakra can then be manipulated to create an effect that would not be possible otherwise, such as walking on water, exhaling fire or creating illusions.
By moulding different ratios of the two energies, new types of chakra can be formed. Most ninja have a natural affinity to one type of chakra, but they have the capacity to create elemental chakra apart from their own affinity. There are five basic types, each stronger and weaker to another, but their relations, weaknesses, and strengths to each other are all explored. There is also the dealing of Yin and Yang and the balance of mental and physical energies. In addition to these five elements, certain kekkei genkai can mix elemental chakra to form new natures, for example it is possible to mix water and wind into ice. While many ninja can use more than one type of chakra, very few are able to use them simultaneously.
Normal chakra is a form of energy all living individuals naturally produce to some degree. Contained in the "chakra coils" that mainly surround and connect to each chakra-producing organ, the energy circulates throughout the body in a network called the "chakra circulatory system" (similar to the cardiovascular system). Certain groups, such as ninja, have learned to generate more chakra and release it outside their bodies through their "chakra points" (tenketsu) in order to perform special techniques (jutsu). Chakra is not normally visible to the human eye, though chakra can be seen in situations where a person releases as much of their chakra as possible. This is rarely seen due to the restrictions of certain chakra points (Eight Gates), limiting the amount of chakra an individual can release at a single given time. Chakra can also be visible when doing a specific techniques (such as the Rasengan) which take a high degree of chakra control to perform.
Of the many different types of techniques, ninjutsu, genjutsu, dōjutsu, and so on, all require the use of chakra. However, taijutsu is different, usually requiring no chakra use whatsoever; stamina is all that is needed. While the ninja still needs a set amount of chakra to live (i.e. life force energy), regular taijutsu doesn't require any active moulding or manipulation of chakra (with few exceptions). A standard attack like a punch or kick falls into this technique category.
Chakra is the resulting form of energy when two other forms of energy are mixed together. The two energies are referred to as "physical energy" and "spiritual energy". Physical energy is collected from the body's cells and can be increased through training, stimulants, and exercise. Spiritual energy is derived from the mind's consciousness (i.e. the soul) and can be increased through studying, meditation, and experience. Having these two energies become more powerful will in-turn make the created chakra more powerful. Therefore, practising a technique repeatedly will build-up experience, building up one's spiritual energy, and thus allowing more chakra to be created. As a result, the ninja is able to do that same technique with more power. This same cycle applies for physical energy, except this time, instead of doing things like meditation, the ninja could, say, do push-ups.
The general term for the source of chakra, the overall physical and spiritual energy an individual has, is called "total stamina". The maximum amount of chakra an individual can create and retain at a given time is called their "chakra level".
In Naruto, chakra takes time and a great deal of training to gradually build up. Thus, the key is not actually having chakra, but being able to sufficiently control and conserve it. Everyone has chakra, but only skilled ninja can correctly "mould" and "manipulate" it to its fullest extent.
Moulding chakra involves the extraction of energies from both the body's cells and the mind's consciousness, then mixing them together within the individual. The amount of each energy will differ based on the type of technique the ninja wishes to execute. In other words, a ninja could create too much or too little chakra for a given technique, resulting in the chakra being used inefficiently. In addition, even if a ninja is able to mould the correct amount of chakra, if they cannot manipulate the chakra properly, the desired technique will not be as effective or will not execute at all. Wasting energy will also create weaknesses like early exhaustion, which would hinder the ninja's capacity to fight long-term battles. General training methods for improving one's moulding and manipulation of chakra are the Leaf Concentration, Tree Climbing, and Water Walking exercises.
As an in-between stage, some ninja can partially manipulate their chakra. This means they can use their chakra, but not effectively control it, which results in a poorly executed technique, a prime example is Naruto trying to use the Academy Clone Technique. To manipulate their chakra more easily, hand seals can be used. With these hand seals, users can control their chakra with higher efficiency, allowing them to execute their techniques more effectively. Different techniques also require the use of different hand seals.
- Shape Transformation deals with controlling the form, movement, and potency of chakra.
- Nature Transformation usually deals with changing the physical properties of chakra into an element. There is also the Nature Transformation of Yin and Yang, which deals with changing the ratio of spiritual and physical energies within chakra.
These two methods can be implemented separately or together in order to create a technique.
The general term for the exact moulding and proper manipulation of chakra is called "chakra control". People with skilled chakra control are usually Medical-nin or Sensor-types, both of which requires extreme control over chakra to be effective. Genjutsu apparently also requires good chakra control.
A good way to build up chakra in the body is to spin it into a tight spiral. Whether to spin the chakra left or right is dependent on the way the user's hair grows, either to the right or left. An opponent can negate a technique by absorbing it and reversing the spin of the chakra within their own body.
Shape of Chakra
Main article: Shape Transformation Most techniques take a certain shape that is usually precisely controlled from one hand to another, through chakra. A good example of this is the Rasengan. Naruto uses one of his hands to control chakra, and moves it over the other in a circular motion, which eventually creates a sphere of pure chakra.
Main article: Nature Transformation Based on which ninjutsu the ninja uses, the amount of chakra will be different, as would the element the ninja employs. The five main elemental types are also the names for the Five Great Shinobi Nations: Fire, Wind, Lightning, Earth and Water. Each ninja has the potential to better utilise one of these styles and potentially more. Rinnegan users somehow have the ability to more easily control all five elements.
Advanced elements such as Wood Release and Ice Release are created by combining different elemental chakra types. Doing this is only possible with a kekkei genkai or having a tailed beast with such an element in canon.
However, the first movie has shown that shinobi of the Land of Snow are able to perform Ice Release techniques without a bloodline by manipulating the ice around them. Kajika was also able to use a water technique that produces ice.
Other Types of Chakra
Tailed Beast Chakra
Main article: Tailed beasts In the Naruto world, there are nine tailed beasts, ancient demons with immense supplies of chakra. In fact, they are nothing more than concentrations of chakra that have taken on a corporeal form (mind and body). During the Great Shinobi Wars, each country's Hidden Village tried to make use of the tailed beasts for military purposes and competed for them. However, no one was ever able to truly bring the tailed beasts under control. The only way to partially control them is to seal them within a human with powerful sealing techniques. The hosts of the tailed beasts are called jinchūriki.
The jinchūriki can tap into the tailed beast's chakra for his or her own power; however, using such chakra can be harmful to the jinchūriki, with the host's body and mind being influenced or even taken over by his or her demon. In the case of Naruto Uzumaki, when he used the Nine-Tailed Demon Fox's chakra and reached his four-tailed form, the chakra was so concentrated around his body that it constantly burned his flesh and repaired his body right away, shortening his lifespan. Tapping into such unnatural chakra is very harmful to the host, as the host's personality gets suppressed by the animalistic blood lust of the tailed beasts and the intensity of chakra will harm the host if used for extended periods of time. As an exception, where the jinchūriki has control over his tailed beasts, these ill-effects are not evident as in the case of Killer B, when he creates a chakra cloak by drawing on part of his tailed beast's power or fully releasing the Eight-Tails' body, no physical damage can be seen from his body. With Naruto having learned to control the Nine-Tails, such damage to his body may now be avoided, but this is yet to be seen.
Main article: Senjutsu
Senjutsu chakra (仙術チャクラ, senjutsu chakura) is the chakra needed to perform senjutsu, which contains the energy found in nature itself. It is a powerful source of energy, able to grant a ninja increased strength, speed, and endurance for taijutsu, as well as enhancing the power of one's ninjutsu and genjutsu. Sage chakra is created through the three-way mixing and balancing of one's physical energy and spiritual energy, as well as the natural energy (自然エネルギー, shizen enerugī) from the atmosphere/air and terrain/ground. Since the three energies need to be equally balanced, the higher one's personal chakra capacity (physical energy and spiritual energy), the more natural energy they can add to the mix. Only those with a such large chakra capacity can gather the natural energy needed for entering a powerful state called Sage Mode. Also, only when a person remains "perfectly still", no longer disrupting the flow of nature around them like ripples in a pond, can they properly feel and harness natural energy. Remaining completely still for a period of time takes a great deal of concentration and patience, requiring a highly motivated and calm state of mind.
Main article: Mysterious Peacock Method By using the chakra enhancing meteorite, shinobi from Hoshigakure can manipulate their chakra into a wide variety of skills at the cost of extreme damage to their bodies. Hoshigakure's method gets its name, Mysterious Peacock, from the chakra's raw manifestation as pinkish purple chakra tails similar to a peacock's tail feathers.
Gift of the Hermit Group
Main article: Gift of the Hermit Group The Gift of the Hermit Group (仙族の才, Senzoku no Sai, English TV: Gift of the Sages) is a special kind of chakra used by the ninja monks of the Fire Temple. It requires daily, unrelenting training to master. This chakra is required to unseal the Sealed Iron Wall granting access to the Fire Temple. It is also required for the technique Welcoming Approach: Thousand-Armed Murder.
Main article: Zero-Tails Dark Chakra (闇のチャクラ, Yami no Chakura) is a special chakra formed from the negative emotions of the heart. Created by the Zero-Tails, as it feeds on the negative emotions of the people around it, it is shown to be extremely powerful, being used to power the Land of the Sky's Ancor Vantian and grants Shinnō powerful techniques with seemingly no drawbacks, though it eventually destroys the mind, and rots the soul of the user.
Main article: Mystic Safety Bell Priestess Chakra (尼僧·チャクラ, Mikö no Chakura) chakra is an aspect bright and unique. It can send pink rays of severing light at her opponents, create a light barrier to shield her from darkness, and transform her into an angelic form. She also used the mystical chakra of the bell to create a protective sphere around a designated target, as she did for Naruto Uzumaki, and use the chakra with Naruto to form the Super Chakra Rasengan.
- Although chakra is usually invisible, those with certain dōjutsu, like the Sharingan, Rinnegan or Byakugan, can see the colour of someone's chakra. Each person's chakra apparently has a different colour. It is also interesting to note the fact that sufficiently immense amounts of chakra are visible to the naked eye.
- It is said that the Sage of the Six Paths was the first to unravel the mysteries of chakra.
- People who are related share similar chakra signatures. In edition to that, those with chakra can see their own chakra signatures. The amount of chakra it takes to be visible depends on how much chakra that person is utilizing. If Naruto when he fought Gaara in The Forest of Death can have visible chakra without help from his Bijuu, then Someone like A will have visible chakra by using just small scale attacks. 
- Chakra signatures also vary among different populations.
- In Naruto Shippūden 4: The Lost Tower, Minato Namikaze and partially supported in the anime episode: Resonance, chakra with similar signatures resonate when they are near.