Futanari (ふたなり, occasionally in kanji: 二成, 二形; literally: dual form, two forms, 二成, 双成, [being of] two types) is a Japanese word meaning hermaphrodite and is used for refer to androgyny.​

Its current use refers to an erotic or pornographic genre, used in comics, anime, eroge and manga, in which intersexual (or altersexual) characters appear, generally with a female body and male genitals, abbreviating the term as futa. Sometimes the genitals are represented only by the penis, without the testicles, and their proportions are usually exaggerated until they reach 30 cm or more than 1 m in length. It is common for the role attributed to men to be reversed, showing futanari characters as dominant.

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In addition to the penis, these characters may have female genitalia. Futanari characters usually have sexual relations with women, and occasionally with men, since this genre is primarily aimed at a male audience.