Chakra Enhancement v1 (
Version 2)
A ninja is able to enhance their body by generating chakra and concentrating it in the necessary areas. By focusing it in the legs they can run faster and jump higher and focusing it in the arms allows them to hit harder and lift a greater amount of weight. The Body Flicker Technique is a ninjutsu based on this concept which supercharges the entire body with chakra so the user can move at extreme speeds, appearing to vanish from sight. The more a shinobi trains their body then the more chakra can be focused within their limbs, meaning that a taijutsu specialist would achieve greater benefits from chakra enhancement than a genjutsu specialist.
Certain individuals have developed unique forms of chakra enhancement that can achieve even greater results than usual. Haruno Sakura developed a jutsu which builds up as much chakra as possible in her fist and releases it at the moment of impact for incredible destructive power. But the most famous example is Tsunade of the Sannin whose super strength is a result of her chakra control and fine-tuning. The only description of how this works is that by instantly collecting chakra into her fist and fingers, she obtains a power of destruction bodily strength alone cannot achieve.
Chakra enhancement isn't limited to the limbs either; it can also be used to enhance the user's senses. By concentrating chakra to the right areas, a ninja's sense of touch, smell, hearing, sight and taste can be enhanced beyond what humans are normally capable. Certain individuals and ninja clans are predisposed towards certain types of enhancement such as the Inuzuka who possess an incredibly sense of smell.
Chakra Sensing (
Official Version)
Everyone has a certain sense that allows them to detect chakra. This sense is most apparent when touching another person or an object that contains chakra however it's possible to sense chakra from a distance. Even with training, for most shinobi that wouldn't extend beyond ten meters unless there's a powerful and/or huge spike of huge chakra.
A smaller percentage of the population are known as Sensors. Their ability to sense chakra extends far beyond what most people are capable of, allowing them to detect targets from a great distance as well as differentiate individuals from their chakra signature alone. They possess an awareness of when other sensors are using their ability. The range and detail of this technique various between sensors as some are so skilled that they can tell when a person is lying or preparing a jutsu whilst others can only tell the general direction of a chakra mass
It's also possible for a ninja to suppress their own chakra to prevent them from being sensed. For most ninja, this doesn't completely hide a person's chakra but it does make them far harder to sense which is useful for stealth and evasion. A sensor on the other hand is essentially able to make themselves completely invisible to chakra sense at the cost of not being able to use their own chakra sensing. It's very difficult to use a jutsu and suppress chakra at the same time due to the needed concentration, usually forcing the ninja to stop the suppression when they need to attack or defend.
Some shinobi have developed specific jutsu which allows them to detect the presence of enemies either because they aren't sensors or to expand the range of their sensory ability. This is known as contact-type sensing. The most notable examples are Nagato creates rain infused with his chakra and Gaara who spreads a special type of sand over an area.
Senjutsu v1 (
Version 2)
This is a form of chakra manipulation which was discovered by the summon animals. As animals they are closer to nature than humans and their instincts led to them learning to harness its power. Not all the summon animals possess knowledge of senjutsu and not all of those that do are willing to pass on their teaching. The ones that do are willing to teach those who sign their clan's summoning contract in blood.
To use senjutsu, it's necessary to possess extreme levels of chakra as it would mean that the user has a body which can use the full potential of this training, one that's capable of handling a foreign energy being introduced into it. The process involves sensing and absorbing natural energy into the body and blending it with their chakra to create the more powerful sage chakra. The user is required to balance their physical and spiritual energy with the natural energy they gather from nature. If the user puts too little natural energy into using senjutsu, the technique will not work and if they gather too much then they transform into an animal and turn to stone. Once a balance has been reached, the user will enter an empowered state known as Sage Mode. Reaching this point means that the user is no longer in danger of turning into a stone animal.
There are two types of Sage Mode; perfect and imperfect. Perfect Sage Mode is achieved when the user is able to perfectly balance natural energy with their chakra. The only part of their appearance which changes is their eyes; usually changing colour, shape and/or gaining markings. The advantages provided by this form are that the user's physical strength, speed, stamina, reflexes, and durability dramatically increase and their ninjutsu, genjutsu, and taijutsu become more powerful. They can harness the natural energy surrounding them, turning it into an extension of their body, which increases the reach of their attacks. Lastly, they gain a sensory ability to detect and identify other people's chakra even from very long distances away, measure the strength of size of someone's chakra and enable them to predict the movements of their enemies.
Imperfect Sage Mode is when the user hasn't achieved a perfect balance of energy, causing their body to take on animalistic properties. The disadvantages of this are that the increase in physical abilities and the strength of their jutsu isn't as great as they would be in the perfected form, and they are unable to harness natural energy as an extension of their body to increase the reach of their attacks. Instead they are capable of transforming parts of their body to become more animalistic which can be useful in combat.
Despite common belief, it isn't necessary for humans to sign a contract with a summon animal for them to use senjutsu. However it's far more difficult for a human to become in tune with nature without a blood bond with summon animals, assuming they even possess the necessary knowledge. And the lack of tools that would prevent them from turning to stone would make it a dangerous and time-consuming endeavour.
When an un-contracted human learns senjutsu, instead of transforming into an animal they remain humanoid but undergo unnatural alterations with the exact features being unique to each individual. The only common features are yellow eyes with a black sclera, skin changing colour, and longer hair, though someone who can use a perfect Sage Mode would only have their eyes change colour. This type of senjutsu is incredibly rare and those that use it are known as Demon Sages.
Land of Water v1 (
Version 2)
Land of Water is an island country floating on the ocean with a very unique culture. It's completely surrounded by water, with most of the land occupied by steep mountains. The smaller islands around the main island each have their own traditions, and many citizens stubbornly insist on preserving these.
When the hidden villages came into being, Kirigakure was the village that was created on the main island of the Land of Water. However it wasn't able to completely unite the shinobi clans of the nation, meaning that various clans could be found on the smaller islands with their own allegiances. The lords of these islands would often war with each other and the main island, resulting in the nation being plagued by endless civil war. They would hire the ninja clans to fight for them which resulted in kekkei genkai clan becoming especially feared as they could use deadly ability without needing to learn them.
To help unify the nation at the end of the last war the bloodline clans were used as scapegoats for the general populace to aim their hate and resentment at. They were persecuted as the bringers of misfortune and many were forced into hiding their bloodline, including the once-powerful Yuki Clan who had been decimated in the war. The Kaguya Clan survived only to destroy themselves by attacking Kirigakure without allies thanks to their warmongering ways.
Kirigakure is one of the few places that kekkei genkai users can live openly but they still suffer from the prejudice created by the civil wars. Whilst civilians of the nation openly despise bloodline holders, shinobi feel a mixture of contempt and fear for them. They are treated like dangerous weapons who serve the village, similar to the jinchuuriki, but most of them find that life preferable to living in fear of death.
But this lifestyle was still wearying. Combined with Kirigakure becoming less powerful and respected among the other nations and the increasingly erratic behaviour of the Fourth Mizukage Yagura during the later parts of his life, discontent grew more and more within the village. Eventually, this culminated in a revolution headed by Terumi Mei who sought to reform Kirigakure. Her desire to better its internal policies, improve the lives of bloodline holders and re-establish diplomatic relations with other countries caused a massive movement that resulted in her dethroned Yagura and become the Fifth Mizukage.
Whilst many found themselves satisfied with this change, Mei's support was not absolute. A year before canon, a rogue faction of shinobi led by Momochi Zabuza instigated a coup d'etat but it ended in failure. He deserted Kirigakure entirely and eventually found himself in Gatou's employment to escape the Hunter-nin Corps and find funding for a second rebellion. But due to the actions of a certain team from Konoha, this never came to be.