Sometimes they will also be termed "for adults" (成人向け, seijin muke) or 18-kin (18禁) (an abbreviation of "forbidden to minors less than 18 years of age" (18歳未満禁止, 18-sai-miman kinshi)).
Nogle benyttes også betegnelserne "for adults" (成人向け, seijin muke) eller 18-kin (18禁), en forkortelse for "forbudt for børn under 18" (18歳未満禁止).