Noticeably, the three main classes of ninja (Genin, Chunin and Jonin) are based from actual ninja ranks used by the historical Iga-ryū school of ninjutsu.
The academy is where would-be ninja start; they are not actually considered ninja until they graduate. Academy students take formal and practical tests of all sorts and are taught basic ninja skills, such as martial arts, techniques, physical fitness and the way of the ninja. Basic weapon usage, such as kunai and shuriken, are commonly taught. Elementary ninja techniques, such as transformation jutsu and clone jutsu, though they vary from village to village, are also taught. Some villages also have an additional test given by the Jonin of each three-man squad to see if they are truly ready to graduate, which determines whether the squad can work as a team. To ensure that only truly qualified ninja are promoted, only three Genin teams are allowed to pass. The test for determining which three teams may become Genin are administered by each team's respective Jonin commander, and vary depending on the Jonin. What is required for graduation varies from academy to academy. In Konoha, the graduation exam is composed of some sort of written test, as well as demonstration of basic techniques, such as clone jutsu, though Rock Lee is an exception, because he can only perform taijutsu.
Genin (下忍?, literally "Lower Ninja", Viz "Junior Ninja") are the lowest level of ninja. Because of this, skill levels vary drastically between Genin. Genin are put in three-man cells, and are then assigned a Jonin sensei to mentor them. This is done to teach the Genin teamwork and experience true ninja life under the supervision and protection of an elite shinobi. The make-up of these teams is based on the individual skills of the Genin, so that there will remain a balance between the teams. When they become Genin, ninja start to do their bit for their village's economy, for which they are given a small payment. They are typically sent either on D-rank missions, which are the lowest rank and are almost entirely risk-free jobs of manual labor, or experienced genin are sent on C-rank missions, which are a cut above that and begin to verge on real "ninja" work, though they generally have a very low possibility of risk to the ninja involved.
Chunin (中忍 Chūnin?, literally "Middle Ninja", Viz "Chūnin" and "Journeyman Ninja") are ninja who are qualified to watch over and guide other ninja. Chunin have reached a level of maturity that primarily consists of leadership skills and tactical prowess. Some of them, like Iruka Umino, function as teachers and others, like Shikamaru Nara, serve as team leaders in charge of small teams who need to make decisions and utilize the skills of the shinobi under their command to the maximum effect. Upon reaching Chunin level, ninja can wear an identifying tactical vest that holds ninjutsu scrolls. This vest is not required; instead, some look for more elaborate clothing like capes or robes. Chunin are typically sent on C or B-rank missions.
To become a Chunin, a Genin participates, with his or her team, in a large examination, known as the "Chunin Exams," hosted twice a year due to the growing number of ninjas. In the past, each village held their own Chunin exam. After the 3rd Ninja World War, allied ninja villages agreed to hold the exams together at the selected village that would host the exam, so villages could improve and strengthen their relationships. Another advantage is that ninja that took the exam might attract clients who are interested in hiring them. The exam is a test not only of strength, but information gathering abilities, survival skills, and adhering to guidelines. Those who have all of these qualities are grouped together into predetermined fights, watched by a council that decides who becomes a Chunin and who does not. While the winners are able to proceed to fight the next opponent, it is aptitude, rather than winning, that is evaluated to determine whether a candidate is promoted. This way even one who loses his or her first match can become a Chunin. In fact, there is a chance that every Genin who makes it to the predetermined fights will become a Chunin, though there is also a chance that every single one will remain a Genin.
Jonin (上忍 Jōnin?, literally "Higher Ninja", Viz "Jōnin" and "Elite Ninja") are generally highly-experienced ninja with great individual skill who serve as military captains. They are often sent on A-rank missions, and experienced Jonin, like Kakashi Hatake, may even be sent on S-rank missions (which are considered to be the most difficult), and may carry out missions alone. They are sometimes assigned as sensei for three-person teams of Genin. Though it is as of yet unknown what one has to undergo to become a Jonin, it is mentioned in the Naruto Anime Profiles that Jonin are appointed. Most Jonin are able to use at least two types of elemental jutsu, have some skills with genjutsu, and have at least above average taijutsu skills.
Tokubetsu Jonin (特別上忍 Tokubetsu Jōnin?, literally "Special Higher Ninja" English "Special Jonin", sometimes known as Tokujō for short) are ninja who, rather than all-around Jonin training, have Jonin-level ability in a single area or skill, much like warrant officers of real-world militaries. They are elite specialists in their areas and are often assigned as subordinates to regular Jonin when their services are needed. They sometimes are seen as lower ranked than jonin because, they are good or the best at one thing and they lack talent, or even ability in others.
Those who have achieved the title of Kage (影?, literally "Shadow") are the leaders of the five most powerful Hidden Villages and generally the most powerful ninja in their respective villages. The Kage stand equally with the rulers of their countries, oversee the activities of their villages, and are the leaders of ninja society. There may be exceptions, however, as a ninja may be the most powerful at the time of being installed as Kage, but may become less powerful upon aging, eventually being surpassed by a more youthful ninja. A Kage may retire and give the title to someone else; the title, once granted, is held permanently, creating a case where there are two Kage at the same time, with only one of them actually active. Their elite status is also attributed to the tendency for most Kage to have family members who were previous Kage, or be personally taught by a former Kage or student of a former Kage, or some combination of these factors. The anime introduced a sixth Kage, the Hoshikage (星影 literally "Star Shadow"?) from Land of Bears. However, this was a self-given title and not officially recognized by the five other villages. Most Kage tend to be at S-Rank level. The five Kage have different titles depending on their village. Those titles are:
- Hokage (火影 literally "Fire Shadow"?) Kage of Konohagakure.
- Kazekage (風影 literally "Wind Shadow"?) Kage of Sunagakure.
- Mizukage (水影 literally "Water Shadow"?) Kage of Kirigakure.
- Raikage (雷影 literally "Lightning Shadow"?) Kage of Kumogakure.
- Tsuchikage (土影 literally "Earth Shadow"?) Kage of Iwagakure.
Classes and Jobs
S-class ninja have gained power far beyond an average Jonin and earned a legendary status. This title is merely a class rather than an actual rank; the ninja's official rank with a village will usually still be Jonin. However, it can sometimes be lower, or they can have no rank at all. The allegiances of these ninja range from being part of the village's own ninja to being wandering ninja who are still loyal to their village. Some ninja of this level tend to leave their villages behind to seek their own ambitions, thus becoming missing-nin. Ninja of this class are often noted in the Bingo book, a list of notable enemy ninja marked for assassination that each ninja village provides for its Jonin and ANBU squad members. Most ninja, even high-level ones, choose to flee rather than face someone of the S-class. Ninja of the S-class are often highly revered, and usually signified by nicknames allies or enemies give them. For example, the Legendary Sannin lit. three people (Tsunade, Jiraiya, and Orochimaru) are all S-class ninja.
The ANBU (暗部?, literally "Hidden Section", Viz manga "Black Ops", English TV "ANBU Black Ops") is actually short for Ansatsu Senjutsu Tokushu Butai (暗殺戦術特殊部隊?, literally Special Assassination and Tactical Squad), and is an organization of assassination squads that serves directly under the village's leader. The ANBU wear porcelain animal masks in order to distinguish themselves from normal shinobi and to conceal their identities, and also have standard uniforms consisting of black and gray armor, arm guards, a signature spiral tattoo on their left shoulder (female ANBU have it on their right shoulder), and a Ninjatō strapped on their back (though certain ANBU wear black cowls over their uniforms). They know the layout of the human body in detail, and have developed several techniques to strengthen their job, such as paralyzing the target. Within the ANBU of Kirigakure, there exists a sub-group called Hunter-nin (追い忍 Oinin?, literally "Chasing Ninja", English TV "Tracker Ninja"), given the specific duty of hunting down missing-nin, and destroying their bodies, so their village's secrets won't be revealed to foreign ninja.
Konoha is shown having two ANBU-like organizations, though are separate from ANBU entirely. The Konoha Military Police Force (木ノ葉警務部隊 Konoha Keimu Butai?, English TV: "Leaf Police"), or Military Police for short, is a unique organization in Konoha, though other villages may have similar organizations. Their symbol is the Uchiha crest because the Uchiha family founded the organization as a sign of trust with the Second Hokage. The Military Police previously consisted of mostly Uchiha clan members, though now Itachi eliminated all but Sasuke, this is no longer the case. The Military Police are in charge of law enforcement within the village, and their jurisdiction is virtually unlimited except in matters that are under the Hokage's direct control, though they also respect ANBU's own investigative system and inner-organization discipline. The Nijū Shotai (二十小隊?, Twenty Platoons) is a task force created by Tsunade, the Fifth Hokage, for the purpose of tracking down, attempting to capture, and, if necessary, eliminating Akatsuki members in the Fire Country. This force consists of twenty four-man teams.
Konoha ANBU are usually under the direct command of the Hokage, but several years before the start of the series there was an ANBU Training Department known as "Root" (根 Ne?). Root was created and directly controlled by Danzo, who trained and conditioned children intensively from a very young age. This was done to completely eliminate emotions and enable its members to complete missions without being held back. Root tends to go further in its belief that ninja must not show any emotion than most other ninja groups do, as they forbid any members to possess anything that may invoke emotion (though Sai somehow has a book that he claims was for his brother). It was implied that the department might have used methods similar to Kirigakure's graduation exam, including putting students against each other in fights to the death. Because Danzo is a war hawk and opposed the Third Hokage, Root was disbanded. However, many former members are still loyal to Root. Even though Root is shown to have been well-intentioned, both Jiraiya and Tsunade remain wary of the organization.
Medical-nin (医療忍 iryō-nin?, English TV "Medical Corps Ninja") are ninja who specialize in medical treatment and use medical-oriented jutsu to heal others. Becoming a medic-nin requires an extreme level of intelligence and excellent chakra control, since medic-nin use chakra to heal injuries. Aside from their medical training, their combat training consists mainly of taijutsu skills, with emphasis placed on evading enemy attacks, as the death of the medic-nin could result in the death of the team, though medical techniques can also be used offensively. On dangerous missions, a medic-nin will usually be sent along with the team, to increase the survival rate of that team. Sakura Haruno becomes a medic-nin after her training with Tsunade.
Missing-nin (抜け忍 Nukenin?, literally "Fugitive Ninja", English TV "Rogue Ninja") are ninja who have abandoned their Hidden Village, and as such can include ninja of every rank. These ninja are considered traitors and are hunted down because of the secrets they may hold. Other Hidden Villages would be interested in purchasing this information because it could be useful in gaining an upper hand in battle or obtaining a bloodline limit unique to a village. Villages create special units of hunter-nin to take care of this problem, although it's unlikely that every missing-nin has a team of hunter-nin sent after them. Also, some may be impossible to find unless they do something to attract attention.