Motoaka

Hi at the base of pectoral fins. Small Hi that is gathered together at the spot where the fin meets the body shows the quality of the Koi's Hi and is a feature of some varieties and patterns. The rest of the pectoral fins must be white. If it cannot easily be seen in a Kohaku when the Koi is viewed from the top then it is acceptable. If it is obvious it is considered a weak point in Kohaku but a feature in Asagi and Showa.

(Courtesy of the excellent Book Kokugyo Vol II)