Mizu-shōbai (水商売), or the water trade, is the traditional euphemism for the night-time entertainment business in Japan, provided by hostess or snack bars, bars, and cabarets. Kabuki-chō in Shinjuku, Tokyo is Japan's most famous area where one can patronize the water trade, as well as its more carnal counterpart fūzoku (風俗)—the sex industry composed of soaplands, pink salons, health, and image clubs.
While the actual origin of the term mizu-shōbai is debatable, it is likely the term came into use during the Tokugawa shogunate (1603–1868). The Tokugawa period saw the development of large bathhouses and an expansive network of roadside inns offering hot baths and sexual release, as well as the expansion of geisha districts and courtesan quarters in cities and towns throughout the country. Bearing relation to ukiyo (浮世 and 憂世), or "the floating world", mizu-shōbai is a metaphor for floating, drinking and impermanence.
According to one theory proposed by the Nihon Gogen Daijiten, the term comes from the Japanese expression "Gain or loss is a matter of chance" (勝負は水物だ shōbu wa mizumono da ), where literal meaning of the phrase "matter of chance", mizumono (水物), is "matter of water". In the entertainment business, income depends on a large number of fickle factors like popularity among customers, the weather, the state of the economy, and success and failure change as rapidly as a flow of water. The Nihon Zokugo Daijiten, on the other hand, notes that the term may derive from the expression doromizu-kagyō (泥水稼業), lit. "muddy water earning business", for earning a living in the red-light districts, or from the Edo-era expression mizuchaya (水茶屋) for a public teahouse.
See also 
- Kenkyusha's New Japanese-English Dictionary, Tokyo 1991, ISBN 4-7674-2015-6
- De Mente, Boyé Lafayette. "Selling sex in a glass! — Japan's pleasure trades". Retrieved 2006-10-03.
- 前田富祺(編)『日本語源大辞典』(小学館)ISBN 4095011815。
- 米川明彦(編)『日本俗語大辞典』(東京堂出版)ISBN 4490106386参照。