先せん輩ぱい後こう輩はい

Meanings

1

one's seniors and juniors; senior-junior relationship

Refers to the pair or relationship between senior (先輩) and junior (後輩) members in a group, emphasizing the hierarchical bond.

先せん輩ぱい後こう輩はいの関かん係けいは日本にほんの職しょく場ばでとても大たい切せつだ。
The senior-junior relationship is very important in Japanese workplaces.
彼かれは先せん輩ぱい後こう輩はいの区く別べつをあまり気きにしない。
He doesn't pay much attention to the distinction between seniors and juniors.

2

seniority-based hierarchy; hierarchical system

Describes the social structure or system where rank is determined by seniority, often in schools, clubs, or companies.

この部ぶ活かつは先せん輩ぱい後こう輩はいの上じょう下げ関かん係けいが厳きびしい。
This club has a strict seniority-based hierarchy.
先せん輩ぱい後こう輩はいの文ぶん化かは日本にほん社しゃ会かいに深ふかく根ね付づいている。
The culture of seniority-based hierarchy is deeply rooted in Japanese society.