In the Elemental Countries, there are places known as shinobi villages. There are many of these villages spread throughout the land, but there are only five that are truly well known. They are known as the Five Great Shinobi Nations.
We have the Land of Earth, which is home to Iwagakure, the Village Hidden in the Stones.
We have the Land of Lightning, which is home to Kumogakure, the Village Hidden in the Clouds.
We have the Land of Water, which is home to Kirigakure, the Village Hidden in the Mist.
We have the Land of Wind, which is home to Sunagakure, the Village Hidden in the Sand.
And finally, we have the Land of Fire, which is home to Konohagakure, the Village Hidden in the Leaves.
Each one of these villages, including smaller nations such as Takigakure or Amegakure, are home to shinobi - the military might and power of a ninja village. These shinobi protect their village and perform missions for a set fee.
In order to do their duty, a shinobi needs to have the ability to do many things. One of the things they need to have is the correct mindset. Eventually, a shinobi will have to end someone's life, whether it be in self defense or on purpose. Another thing they might have to do is something that goes against their morals. A person working to become a shinobi should be aware of this and not be disillusioned just because of the respect a shinobi gets.
A person who's willing to be a shinobi must also be physically capable. Shinobi are known to jump from building to building, run long distances without stopping, and having an advance endurance level. A person who's willing to become a shinobi must also be willing to train their bodies to an extent that allows them to perform these tasks and more.
And finally, a person who's willing to become a shinobi must be able to mould their chakra affectively. Every living thing, whether it be a person or an animal or a plant, has chakra inside of them. A shinobi can mould and shape their chakra to use in jutsu to attack an enemy or defend an ally.
There are three different types of jutsu that shinobi use; Taijutsu, Genjutsu, and Ninjutsu.
Taijutsu refers to any type of attack that utilizes martial arts and relies on strength and stamina from training to perform. Although taijutsu doesn't normally use chakra, it can be enhanced by using it. Taijutsu, simply put, is hand-to-hand combat and is used by almost every shinobi.
Genjutsu refers to illusions. Using chakra, a shinobi can make an enemy see, hear, or feel things that aren't actually there. This technique requires decent chakra control and not normally used by people with large chakra stores. Not many shinobi use genjutsu as an offensive technique, merely as distractions and misdirects.
And finally, Ninjutsu, the most commonly used jutsu of shinobi. Ninjutsu is probably the most used technique for attacks. It requires decent chakra control and an appropriate amount of chakra as well. In the most simplest of terms, ninjutsu is everything that isn't genjutsu or taijutsu.
Another thing shinobi use, other than jutsu, are weapons. Whether it be swords or kunai or ninja wire, a shinobi always has weapons on their person.
A shinobi is also a loyal soldier to their village. Those who betray their village or no longer holds its best interest at heart are declared as rogue shinobi, or 'missing-nin'. They are then declared to be either killed on sight or captured.
They are many great shinobi in each of the Five Great Shinobi Nations, some had even become legends.
However, it seems lately that most infamous shinobi hail from Konoha, the Village Hidden in the Leaves. Some examples include Asuma Sarutobi, one of the Twelve Guardians of the Daimyo. Kakashi Hatake, the copy-nin. Maito Guy, taijutsu specialist, and all four of the hokages.
And now, we get to see three more shinobi from the Leaf Village, well on their way to becoming infamous shinobi themselves.