The chonmage (丁髷, ちょんまげ) is a form of Japanese traditional haircut worn by men. It is most commonly associated with the Edo Period and samurai, and in recent times with sumo wrestlers.
The hair is grown long. It is oiled and tied into a ponytail which is then folded up onto the top of the head giving a so-called topknot. In the Edo Period the top of the head was usually shaven.
Modern Sumo wrestlers do not have the area shaven, although the hair may be thinned in this region to allow the topknot to sit more neatly. Sumo wrestlers with sekitori status are allowed, on certain occasions, to wear their hair in a more elaborate form of topknot called an oicho, or ginkgo leaf, style, where the ends of the topknot are splayed out to form a semicircle. Given the uniqueness of the style in modern Japan, the Sumo Association employs specialist hairdressers called tokoyama to cut and prepare sumo wrestler's hair.