is a Japanese term for men who have a culturally feminine gender expression. This includes amongst others males with feminine appearances, or those cross-dressing. is a play on the word ("boy", from the characters for 'male' and 'child'), which is also pronounced ; in the slang term, the kanji for "child" () is substituted with "daughter"/"girl" ().
The term originated in Japanese manga and Internet culture in the 2000s, but the concept reflects a broad range of earlier traditions and examples of male cross-dressing in Japan, such as in kabuki theater. Its popularity increased around 2009, with the rise of dedicated maid cafés, fashion stores, cosmetic products, and a range of popular media in the culture. It is often combined with the cosplay of female fictional characters by men (crossplay).
By extension, is also a genre of media and fiction about feminine-looking or feminine-dressing men, and often contains erotic or romantic elements. It is mainly aimed at male audience but also appears in a lot of manga. characters have also begun to appear in mainstream Japanese popular entertainment such as manga, anime, and video games.