Snow ring
雪輪 yukiwa

The scalloped outline of a snow crystal; snow foretells a good harvest, so yukiwa is auspicious, and its cool shape is also used on summer kimono.
Edo period (stylised form); snow imagery goes back to the Heian period
Falling snow was taken as a sign of a good harvest, and snow imagery is said to go back to the Heian period. The yukiwa, a circle with six soft scallops based on the snow crystal, developed during the Edo period; a 17th-century kosode in the Met is covered with yukiwa filled with small flowers. It spread among townspeople, especially women, and was later varied by layering, shading and filling with other patterns.
Used in winter but also, for its cooling look, on summer kimono and yukata.