Washio Kyoumaru (鷲尾京丸 Washio Kyōmaru?) is Yellow Diamond (イエローダイヤモンド Ierō Daiyamondo?) the Yellow Ranger of the Crystalrangers. Kyoumaru is a member of the Otaku Club as well as the Art Club and is shown to have the highest grades in his school next to his teammate, Otorimine Haruka . Despite his nerdy reputation, Kyoumaru gets along with most of the students very well and is very strict when it comes to studying, thus getting on Toranosuke and Zenjirou about their homework. His Shinsei Stone is the yellow Diamond, and his Gemstone Beast is the Diamond Eagle. His element is Electricity (Thunder) and he has an older brother named Shishido Seiji .