See also: Ninja Ranks
Chūnin (中忍, Literally meaning: Middle Ninja, Meaning (Viz): Journeyman Ninja) are ninja who have reached a level of maturity and ability that primarily consists of leadership skills and tactical prowess. Chūnin are typically sent on C-rank or B-rank missions. Some of them, like Iruka Umino and Shino Aburame move on to become Academy teachers.
To become a chūnin, a genin participates in a large examination, known as the Chūnin Exams. Those who pass the test and become chūnin are eligible to 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.