Senjutsu (仙術, Sage Techniques) 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 dimension of power to the Sage's chakra, resulting in the creation of "senjutsu chakra" (仙術チャクラ, senjutsu chakura).
This new chakra enables the user to enter an empowered 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 sage (仙人, sennin). 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.
The user's ninjutsu, genjutsu, and taijutsu become very powerful.
The user can have the natural energy surrounding them, becoming an extension of their body, increasing the reach of their attacks.
The user gains the ability to sense chakra around them.
The user does not feel as much pain against physical damage.
edit Weaknesses If the user draws in too much natural energy in the attempt to initiate Sage Mode, they run the risk of transforming into a toad, then into stone.
In order to gather enough natural energy to initiate the transformation into Sage Mode, the user must remain perfectly still. Because of that, the user can be an easy target for an opponent.
Because the user needs to move during combat, the Sage chakra cannot be replenished, which means the user can't stay within this state for extended periods of time.
The two weaknesses mentioned above can be bypassed through the Sage Art: Amphibian Technique, where one Sage gathers chakra for another or as in Naruto's case, shadow clones can be used for the same purpose.
After Sage Mode has ended, the user appears to experience exhaustion.
edit Forms [edit] Imperfect Sage Mode Jiraiya was not able to properly balance his own chakra with natural energy, resulting in him using an imperfect form of Sage Mode. So, whenever Jiraiya was using Sage Mode, he would summon Shima and Fukasaku by drawing a blood contract on his face to assist him in using Sage Mode.[2] The Toad Elders fused to Jiraiya's shoulders with Sage Art: Amphibian Technique, gathering natural energy from their stationary positions for Jiraiya's use.
As a result of the imbalance (and the imperfect nature of his transformation), Jiraiya took a number of toad-like traits when using Sage Mode. His appearance was altered (he has a bigger nose, excess hair (his goatee), and toad-like eyes. Further transformational attributes includes him taking on a toad-like stature and the lines on his face become much thicker, taking over each side of his face. Because of these traits, Jiraiya didn't like to use Sage Mode as it "displeases the ladies". He also showed the ability to transform his limbs (e.g. his hands and feet) into those of frogs so as to aid in maneuverability.
True Sage Mode
Naruto in Sage Mode, the pigmentation around his eyes being the mark of a true Sage.Unlike Jiraiya, Naruto is able to perfectly balance the natural energy with his own chakra. This allows him to use the true Sage Mode, which retains all of his usual physical characteristics except for toad-like eyes. A true sage would still suffer from the weaknesses of Sage Mode, requiring that they use Sage Art: Amphibian Technique in a battle situation. Because of the Nine-Tailed Demon Fox sealed within Naruto, however, Shima and Fukasaku were rejected whenever they tried to fuse with him.
As a workaround, Naruto has some of his shadow clones gather natural energy elsewhere while he fights. Once he has run out of his own senjutsu chakra, he has one of the clones disperse, giving him the clone's natural energy and allowing him to enter Sage Mode again. This method limits the maximum number of shadow clones that Naruto can create to five for as long as the clones are gathering natural energy, as anything more would interfere with their focus. To make sure he has enough shadow clones for use in battle, Naruto has only two shadow clones gather senjutsu chakra, allowing him to enter Sage Mode a total of three times. Naruto also stated that it is possible to lengthen the time he is in Sage Mode.
Nine-Tails Influence
The Sage Mode's eyes combined with the Nine-Tails'.During his meeting with Nagato, Naruto is stabbed in the gut with the former's chakra disruption blade. Nagato thinks that he would be able to control Naruto with his own chakra, but Naruto reveals a fusion of his initial jinchūriki form and Sage Mode characteristics. The exact capabilities of this form are unknown, but it is enough to completely resist Nagato's control.
