datehyogo
A traditional Japanese hairstyle (nihongami), and a subtype of the hairstyle; also transliterated as tatehyogo.
Unlike the yokogyogo (横兵庫) hairstyle's more triangular shape, the the datehyogo has a more rounded appearance. These two styles of hair can be hard to individually discern in images, however, as art styles can cause the shape to vary.
This style stems from oiran, high-class courtesans of Edo Japan. It evolved from the more bow-shaped ryohyogo.