Kohai

Senpai (, "earlier colleague") and kōhai (, "later colleague") are terms from the Japanese language describing an informal hierarchical interpersonal relationship found in organizations, associations, clubs, businesses, and schools in Japan. The concept is based in Japanese philosophy and has permeated Japanese society.

The relationship is an interdependent one, as a senpai requires a kōhai and vice versa, and establishes a bond determined by the date of entry to an organization. The kōhai defers to the senpai's seniority and experience, and speaks to the senpai using honorific language.

The relationship is an interdependent one, as a senpai requires a kōhai and vice versa, and establishes a bond determined by the date of entry to an organization.Senpai refers to the member of higher experience, hierarchy, level, or age in the organization who offers assistence, friendship, and counsel to a new or inexperienced member, known as the kōhai, who must demonstrate gratitude, respect, and occasionally personal loyalty. The Senpai acts at the same time as a friend. This relation is similar to the interpersonal relation between tutor and tutored in Eastern culture, but differs in that the senpai and kōhai must work in the same organization.

The relation originates in Confucian teaching, as well as the morals and ethics that have arrived in Japan from ancient China and have spread throughout various aspects of Japanese philosophy. The senpai–kōhai relation is a vertical hierarchy (like a father–son relation) that emphasizes respect for authority, for the chain of command, and for one's elders, eliminating all forms of internal competition and reinforcing the unity of the organization.

Over time this mechanism has allowed the transfer of experience and knowledge, as well as the expansion of acquaintances, to mainting the art of teaching alive. It also allows the development of beneficial experiences between both, as the kōhai benefits from the senpai's knowledge and the senpai learns new experiences from the kōhai by way of developing a sense of responsibility. The senpai–kōhai relation involves a comradeship that does not cross gender bounds; a male does not refer to a female as senpai. This comradeship does not imply friendship; a senpai and kōhai may become friends, but such is not an expectation.

...
Wikipedia