Odango (hairstyle)

A bun is a type of hairstyle wherein the hair is pulled back from the face, twisted or plaited, and wrapped in a circular coil around itself, typically on top or back of the head or just above the neck. A bun can be secured with a barrette, bobby pins, one or more hair sticks, a hairnet, or a pen or pencil. Hair may also be wrapped around a piece called a "rat". Alternatively, hair bun inserts, or sometimes rolled up socks, may also be used to create donut-shaped buns. Buns may be tightly gathered, or loose and more informal.

Double or pigtail buns are often called odango (お団子, odango^?) , which is also a type of Japanese dumpling (usually called dango; the o- is honorific).

The term was popularized by the anime and manga series Sailor Moon, whose eponymous heroine, her mother during the Ancient Silver Millennium, Queen Serenity, and her future daughter from the 30th Century Silver Millennium, Chibiusa (although Chibiusa's are more conical than spherical), all wear their hair in this style. They also wear two pigtails of hair that hang down from the two spherical buns, but this is not universal to the term's usage within Japan, itself. The term odango in Japanese can refer to any variety of bun hairstyle.

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Wikipedia