Chūnin (中忍; Literally meaning "Middle Ninja", Meaning (Viz) "Journeyman Ninja") are ninja who are qualified to watch over and guide other ninja. Chūnin have reached a level of maturity that primarily consists of leadership skills and tactical prowess. This is because the genin who don't have the skills to become chūnin are weeded out in testing. Some of them, like Iruka Umino and Mizuki, function as Ninja Academy 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. Chūnin are typically sent on C-rank or B-rank missions.
To become a chūnin, a genin participates in a large examination, known as the chūnin exams . The only exam seen in the series is a three-stage exam held in Konohagakure. Those who pass the test and become chūnin can wear an identifying flak jacket that holds ninjutsu scrolls. This vest is not mandatory; instead, some opt for more elaborate clothing like capes and robes.