structural:summarization, stylistic:style_transfer
Clothing

Sumo wrestlers wear mawashi, a 30-foot-long belt, that they tie in knots in the back. They have an official thickness and strength requirement. During matches, the wrestler will grab onto the other wrestler's mawashi and use it to help them and make moves during a match. The mawashi they wear practicing versus in a tournament is essentially the same except for the material. The different mawashi that the wrestlers wear differentiate their rank. Top rated wrestlers wear different colors of silk mawashi during tournament, while lower rated wrestlers are limited to just black cotton.

Their hair is put in a topknot, and wax is used to get the hair to stay in shape. Wax is applied to sumo wrestlers' hair daily by sumo hairdressers (tokoyama). The topknot is a type of samurai hairstyle which was once popular in Japan during the Edo period. The topknot is hard for some foreigners' hair because their hair is not as coarse and straight as Japanese hair. Once a wrestler joins a stable, he is required to grow out his hair in order to form a topknot.

Outside of tournaments and practices, in daily life, sumo wrestlers are required to wear traditional Japanese clothes. They must wear these traditional clothes all the time in public. What they can wear in public is also determined by rank. Lower rated wrestlers must wear a yukata at all times, even in winter, where higher rated wrestlers have more choice in what they wear.