Chakra can only come from 3 or 2 places:
- (1) Physical Energy (身体エネルギー, shintai enerugī) inherent in the trillions of their cells.
- (2) Mental Energy (精神的能力, Seishin-teki nōryoku) also known as Spiritual Energy (精神エネルギー, seishin enerugī) gained from basic everyday exercise and experience of meditation. In order for a shinobi to perform a perfect jutsu, the user will bring out and release these two energies together molding them. The amount of chakra required for a technique will vary depending upon its size and complexity. Each shinobi has the potential to better utilize an elemental Ninjutsu style.
By only focusing an equal and constant amount of chakra to a portion of the shinobi's own body allows them to attach their body to the given touched object. This would allow them to walk up vertical or ridged surfaces. By expelling a continuous set amount from their feet in proportion to their body weight, the shinobi can walk on water. With enough training a shinobi can also focus chakra to specific limbs, which will increase the physical muscles which enables them to have enhanced power and strength.
Chakra can also be extended from the body for attack and defense. This can take the form of the chakra strings used to manipulate puppets in Kugutsu no Jutsu like Sasori. It can also be focused to a fine point for cutting, such as in Kabuto Yakushi's Chakra Scalpel. It can also be used to form a defensive barrier in Chakra like Nagato's Shinra Tensei.
The chakra in the brain can also have sensory organs which are also the primary target of Genjutsu. Genjutsu is created when a ninja extends their chakra flow through the cerebral nervous system of their opponent to control their minds chakra, thereby affecting their five basic senses. To combat the effects of Genjutsu, there are two options which has been stated by Lady Chiyo. The 1st option is for the ninja to stop the flow of chakra in their entire body, and then apply an even stronger power to disrupt the flow of the casters chakra. The 2nd option is to have an outside ninja unaffected by the Genjutsu make physical body contact, and use their chakra to disrupt the casters flow.
According to what Madara Uchiha had spoken about, is that chakra was originally a energy that belonged to the Shinju. And when the princess Kaguya Otsutsuki had ate the forbidden fruit the Shinju had grown only a every 1,000 years. She had become the first person in history to wield and use chakra. With her new power she ended the wars that had plagued the lands. One of her son's, Hagoromo Otsutsuki, a powerful being who would become known as the Sage of the Six Paths, which he was 1st born child with chakra the 2nd only along with his brother Hamura Otsutsuki with chakra. It was Hagoromo who spread chakra to others, intending for the chakra to connect people's spiritual energy so that they would understand one another without even talking or physical contact. This became known as Ninshū (忍宗,"Shinobi Sect"), with his goal being to lead the world toward peace. But this was turned aginst his own dream when the people who gained and was taught ninshu did not use it in the way the Sage had hoped, instead using the chakra to connect their inner spiritual and physical energies. They had used their inner chakra to amplify and weaponize it, becoming what is now known as Ninjutsu. In the end, they ended up using their chakra in battle, just as Hagoromo's mother Kaguya did many years ago.
Once the famed Hagoromo Otsutsuki had finished spreading his chakra, it has long since been a form of Life Energy (生命エネルギー,Seimei enerugī) that all living individuals produce."Chakra Points" (Tenketsu) in order to perform special techniques also known as modern jutsu. Chakra isn't normally visible to the human eye, though chakra can be seen in situations where a person releases as much of their chakra as possible like Naruto Uzumakiwhen he is enraged. Chakra being able to be visible only when doing specific techniques (such as the Rasengan or Asuma Sarutobi's chakra weapon's) which take an even higher level of chakra control/manipulation to perform. Shinobi can find Chakra in, ninjutsu, genjutsu, and even dojutsu which they all require a level amount of chakra.