In The History of Hentai Manga, hentai manga researcher Kimi Rito states that ahegao follow three particular traits that set them apart from other ikigao (orgasm face) expressions: A number of non-adult works feature ahegao faces, often in a porn-parodying manner. While ahegao is often used in pornographic manga, anime, and videogames, it is not exclusively a term of hentai. Ahegao indicates that the pleasure experienced is so powerful that the character loses control of their facial expression.
An ahegao face of various levels of distortion is used to depict different grades of sexual arousal. Depictions of ahegao are often drawn intentionally exaggerated to create a surreal effect. A character's overall face shape may also be distorted in ahegao scenes. Typical characteristics are rolled or crossed eyes, a hanging tongue, and flushed cheeks. Others are acmegao (アクメ顔) from the French loanword acmé (orgasm), and yogarigao (よがり顔) 'satisfaction face'. One of these is ikigao ( イキガオ) meaning 'coming face'. There are several other names for the facial expressions made at the moment of orgasm. Thus, ahegao can be interpreted as 'moaning or panting face.' The second part, gao or kao ( 顔) means 'face'. The first part of the term, ahe ( katakana: アヘ) is an abbreviation for aheahe ( アヘアヘ), an onomatopoeia for 'pant' or 'moan'.
