buddhist nun
A female nun in Buddhism, much like the Catholic counterpart, otherwise known as bhikkhunī generally (bikuni or ama in Japanese), or nisou in Japanese.
Usually in real life, they are known for their bald hair (as a requirement for Buddhist monastics) and robes. This is not always universally applied however, and in Japan, some Buddhist nuns do still grow their hair or if are bald, wear wigs. Bald Buddhist nuns in manga are less commonly depicted.
In Japan, they also wear a white wimple similar to those worn by Catholic nuns.