Translation guide
Refers to sexual relations that are forbidden by law, custom, or morality. In Japanese, this concept is expressed through specific legal terms, euphemisms, and descriptive phrases depending on the context (adultery, prostitution, statutory offenses, etc.).
Sexual relations between a married person and someone other than their spouse.
The most common and general term for an extramarital affair. Widely used in media and everyday conversation.
彼は不倫が原因で離婚した。
He got divorced because of an affair.
A formal, legalistic term for adultery. Rarely used in daily speech; mostly found in legal contexts or historical texts.
姦通罪は1947年に廃止された。
The crime of adultery was abolished in 1947.
Engaging in sexual activity in exchange for money, often illegal or regulated.
The standard term for prostitution. Can be used in legal, social, and news contexts.
売春は法律で禁止されている。
Prostitution is prohibited by law.
Refers to the act of purchasing sexual services. Often used in discussions about the demand side of prostitution.
Sexual intercourse with a person below the age of consent, which is illegal regardless of apparent consent.
A descriptive phrase meaning 'sexual intercourse with a minor'. Used in legal and news reports.
未成年者との性交は法律で罰せられる。
Sexual intercourse with a minor is punishable by law.
A legal term often used specifically for sexual acts with minors, especially in the context of '淫行条例' (ordinances against obscene acts with minors).
彼は淫行条例違反で逮捕された。
He was arrested for violating the ordinance against obscene acts with minors.
Sexual relations between close relatives, which is illegal and taboo.
The standard term for incest. Used in psychological, legal, and social discussions.
近親相姦は多くの文化でタブーとされている。
Incest is taboo in many cultures.
Any sexual activity considered illegal or immoral, not covered by the above categories.
A broad, formal phrase meaning 'inappropriate sexual relations'. Suitable for contexts like workplace misconduct or abuse of authority.
教師と生徒の不適切な性的関係が問題になった。
Inappropriate sexual relations between a teacher and a student became a problem.
An archaic or literary term for secret sexual relations, often adulterous. Rarely used in modern conversation.
The English phrase 'illicit intercourse' is very formal and legalistic. In most everyday contexts, Japanese speakers use more specific terms like 不倫 (adultery) or 売春 (prostitution). Using a direct translation like 不法性交 (ふほうせいこう) would sound unnatural and overly technical.
不倫 (ふりん) specifically refers to an extramarital affair involving a married person. 浮気 (うわき) is a broader term for cheating or infidelity, which can apply to unmarried couples as well. 浮気 may or may not involve sexual intercourse, while 不倫 implies a sexual relationship.
彼氏が浮気した。
My boyfriend cheated on me.
不倫は離婚の原因になる。
An affair can lead to divorce.
買春も違法行為とみなされる場合がある。
Purchasing sexual services can also be considered illegal.
昔の小説には密通の場面がよく描かれている。
Old novels often depict scenes of secret liaisons.