不ふ純じゅん異い性せい交こう遊ゆう

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じゅ

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い

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Meanings

noun

illicit sexual relationship; improper relations with the opposite sex

A formal or euphemistic term for a sexual relationship considered morally or socially inappropriate, often used in legal, educational, or disciplinary contexts.

教きょう師しと生せい徒との不ふ純じゅん異い性せい交こう遊ゆうが問もん題だいになった。
The illicit relationship between the teacher and student became a problem.
校こう則そくで不ふ純じゅん異い性せい交こう遊ゆうは禁きん止しされている。
Improper relations with the opposite sex are prohibited by school rules.

Kanji

不negative, non-, bad
純genuine, purity, innocence
異uncommon, different, queerness
性sex, gender, nature
交mingle, mixing, association
遊play

Related words

不ふ倫りん
不倫 specifically refers to adultery or an extramarital affair, while 不純異性交遊 is a broader, more formal term for any improper sexual relationship, not necessarily involving marriage.
淫いん行こう
淫行 is a stronger, more condemnatory term for sexual misconduct or lewd acts, often with a criminal connotation, whereas 不純異性交遊 is a milder, bureaucratic expression.

Built from

不ふ純じゅん+異い性せい+交こう遊ゆう

Etymology

Compound of 不純 (impure, improper) + 異性 (opposite sex) + 交遊 (socializing, association). The exact origin is uncertain, but it likely arose in formal or institutional settings to describe relationships deemed inappropriate.