It is a pattern of waves. This pattern was used in the dance costumes for the famous ancient court music called ‘seigaiha.’ That’s why it’s called seigaiha.

This pattern has various types such as a repeating pattern of colorful semi-circular overlapping waves, a wave pattern in the style of Japanese ukiyo-e, a kiku-seigaiha pattern (a wave pattern combined with chrysanthemum) or kanoko-seigaiha pattern (a wave pattern created in the style of kanoko).