Shunga ('spring pictures'), originally a Chinese expression, is the name given to erotic Japanese paintings, prints and illustrations.
Traditional Shintō beliefs and fertility rites venerated the joyful union of the sexes, and Japanese morality was never constrained by strict Confucianism to the same degree as in China and Korea. The depiction of the sexual act was not considered to be inherently sinful or degrading. The earliest shunga appear as graffiti hidden on seventh-century Buddhist statues and in sophisticated eighth-century sex manuals, often based on Chinese originals. From the twelfth century onwards, painted shunga emaki ('handscrolls') probably became an established art-form among the priesthood, aristocracy and samurai classes.
With the spread of woodblock printing in the seventeenth century, erotic art became more freely available and popular with the city merchant classes. The first dated shunga publication, a printed book, was published in Edo in 1660 and shunga was an accepted part of the repertoire of Ukiyo-e artists from the earliest period of the school. Erotic works sometimes represented up to one-fifth of an individual artist's total output.
With the development of full-colour printing around 1765, shunga experienced a high point, led by artists such as Harunobu, Kōryūsai and Kitagawa Utamarō. Several nineteenth-century artists, including Hokusai, also made notable erotic works. The westernization of Japanese culture in the late nineteenth century inevitably brought prudish Victorian values, and it is only in recent years following the relaxation of strict censorship that there has been a revival of appreciation of shunga as an art form in Japan.