Senpai and kōhai

The senpai (先輩, "senior") and kōhai (後輩, "junior") relationship has its roots in Confucianism, but has developed a distinctive Japanese style.

The relationship is an interdependent one, as a senpai requires a kōhai and vice versa,[1] and establishes a bond determined by the date of entry into an organization.

[5] 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.

[3][4] Over time this mechanism has allowed the transfer of experience and knowledge, as well as the expansion of acquaintances and the building of institutional memory.

[12] Confucianism arrived from China between the 6th and 9th centuries, but the derived line of thought that brought about deep social changes in Japan was Neo-Confucianism, which became the official doctrine of the Tokugawa shogunate (1603–1867).

[13] The Japanese family system (家 ie) was also regulated by Confucian codes of conduct and had an influence on the establishment of the senpai–kōhai relation.

This was called koshusei (戸主制, "family-head system"), in which the head of the household had the right to command his family and the eldest son inherited that position.

A person who speaks respectfully to a superior uses honorific language (敬語 keigo), which is divided into three categories:[15][14] Sonkeigo and kenjōgo have expressions (verbs, nouns, and special prefixes) particular to the type of language; for example, the ordinary Japanese verb for "to do" is suru, but in sonkeigo is nasaru and in kenjōgo is itasu.

It is common in school sports clubs for new kōhai to have to perform basic tasks such as retrieving balls, cleaning playing fields, taking care of equipment, and even wash elder students' clothes.

The rules of superiority between a senpai and a kōhai are analogous to the teacher–student relation, in which the age and experience of the teacher must be respected and never questioned.

Kōhai no longer show as much respect to the experience of their senpai, the relation has become more superficial, and the age factor has begun to lose importance.

[4] The collapse of the economic bubble in the early 1990s caused a high level of unemployment, including the laying off of high-ranked employees.

Most Japanese people—even those who criticize it—accept the senpai–kōhai system as a common-sense aspect of society, straying from which would have inevitably negative social consequences.