There are many variation in Saru masks: young, old, male and female, just like in a monkey family. The mask of a child monkey is used for "Utsubo-zaru," where a child actor often makes his stage debut. "Saru-muko"also uses a Saru mask. It is the stiry about a monkey who adopts a son-in law into his family. This human-like mask maybe worn by the father monkey.