Since around the Heian period, young trainee monks (age 12 to about 18) who did not shave their heads began to appear at the large-scale temples of the Shingon and Tendai sects of Buddhism, and these boys came to be called chigo.
平安時代頃から、真言宗、天台宗等の大規模寺院において、剃髪しない少年修行僧（12～18才くらい）が現れはじめ、これも稚児と呼ばれる様になった。