Kohai

Senpai (先輩, "senior") and kōhai (後輩, "junior") are Japanese terms used to describe an informal hierarchical interpersonal relationship found in organizations, associations, clubs, businesses, and schools in Japan and expressions of Japanese culture worldwide. The senpai and kōhai relationship has its roots in Confucianism, but has developed a distinctive Japanese style. The term senpai can be considered a term in Japanese honorifics.