Senjutsu

refers to a specialized field of jutsu that allows the user to sense and then gather the natural energy around a person. Senjutsu practitioners can then learn to draw the energy of nature inside of them blending it with their own chakra, (created from spiritual and physical energy within the shinobi,) adding a new dimention of power to the Sage's chakra, resulting in the creation of.

This new chakra enables the user to enter a powered state called Sage Mode, which can then drastically increase the strength of all ninjutsu, genjutsu, and taijutsu. A person who is able to use senjutsu is called a. It would seem that it stems from the toads of Myōbokuzan, as only Shima, Fukasaku, Jiraiya and Naruto have been seen using it. Gamakichi and Gamabunta also seem to be familiar with it.

Very few people have been shown to be able to master the art of senjutsu. Since the energy of nature of energy is emmense, only those who already have enormous chakra capacities will have the capacity to go on and draw upon it. If the practitioner can achieve a perfect balance between the physical and spiritual energies of their own chakra, and the energies of nature, combining it with their own chakra, produces a new and stronger chakra, called "Sage Chakra": In order to explain this to Naruto in a way that he could understand it, Gamakichi likens the process of adding natural energy to one own physical and spiritual energies to adding an extra flavor to a Chocolate and Vanilla Swirl Ice Cream.

Those able to do so, be they Toad or Human, are able to enter a physical state, called "Sage Mode", the physical activation of ones own body in many ways, such as strength, speed, stamina and endurance, such as was exhiberted during the 'Senjutsu Training' arc, when Naruto fell from a balancing spike, during his senjutsu training with Fukasaku in order to master stillness; Naruto remained unharmed and felt hardly any pain. The strength and potency of the Sage's Taijutsu, Ninjutsu and Genjutsu are also increased drastically and dramatically in range, scope and power.

Naruto and Jiraiya are the only two human beings who are seen using it, with Naruto the only one of the two to master it. This is because Senjutsu training should never be undertaken lightly, as the risks involved are high: If the practitioning Sage should be unable to reign in control of their 'sage' chakra, the results can be disasterous; if the sage cannot draw on enough natural energy, then they cannot achieve 'sage mode'.

Likewise, if they should draw too deeply into nature, they will literally become apart of nature itself, their very body transmuted into solid stone, and transformed into the shape of a man-sized toad. There are many toad sculptures surrounding the fountain of the Shinobi-Toads Secret Toad Oil hidden on Myōbokuzan - all of these statues are the petrified remains of one-time apprentice Sages' who failed to master the art of senjutsu after taking in too much of natures power.

Usage
Only those who already possess a high-level chakra capacity can invoke senjutsu. The user is required to balance his/her physical and spiritual energy with the natural energy he/she gathers from nature. If the user puts too little natural energy into using senjutsu, the technique will not initiate. If the user puts too much natural energy into the techniques, the user will start to turn into a toad and, eventually, turn to stone. Furthermore, while gathering natural energy, the gatherer must remain absolutely still in order to be one with nature.

Getting hit by a special scepter during the transformation will reverse the Toad Transformation by knocking all the natural energy out of the gatherer. It is dangerous to learn how to gather natural energy without the staff because there is no other known way to reverse the toad transformation. Furthermore, if the transformation is completed, not even the staff can reverse it, and the user would become a toad statue forever.

Sage Mode
Jiraiya had trouble using Sage Mode, as he slightly turns into a toad whenever he uses this form. This involved his nose and eyes (although the eyes can be excluded because as Fukasaku said the "toad eyes" are always present in Sage Mode being the sign of a true Sage) changing to a more toad-like appearance. Also, he grows a goatee just like Fukasaku's and his fingers and toes are toad-like.

However, Naruto, who has just learned how to sense natural energy and create sage chakra, only has red rings around his eyes and horizontal, golden slitted-pupils, showing his mastery over his Sage form--Naruto's rapidly aquired mastery of Sage Mode may be owed in part to his prior experiences in "Jinchūriki Mode". Naruto is able to use his Sage chakra very well, demonstrating the ability to lift a giant toad statue with his Sage chakra augmenting his physical strength so soon after his induction to Senjutsu.

Before Naruto was able to utilize the Sage chakra correctly and evenly, he used toad oil, which allowed the natural energy to enter his body. However, the oil involved can only exist in liquid form in Myōbokuzan's atmosphere, and evaporates if it is taken outside, thus forcing Naruto to gather natural energy on his own. Jiraiya was able to continuously draw in natural energy by having Fukasaku and Shima remain motionless on his shoulder while he fought, but the Nine-Tailed Demon Fox rendered this impossible for Naruto.

In order to work around this problem, Naruto had two of his clones gather natural energy, and dispelled one when he ran out, gaining the clones' Sage chakra. Furthermore, usage of high-level techniques while in Sage Mode can hasten the exhaustion of the user's Sage chakra reserves, as was seen when Naruto quickly reverted to normal after he fired a Wind Release: Rasenshuriken at Pain's Human path and a Sage Technique: Rasenrengan at Pain's Animal path.