Yukako Yamagishi (山岸 由花子 Yamagishi Yukako) is a secondary ally featured in the fourth part of the JoJo's Bizarre Adventure series, Diamond is Unbreakable. Yukako is a high-school student besotted with Koichi Hirose. She originally tries to kidnap Koichi before being neutralized and eventually starting a mutual relationship with him. Struck with the Arrow by Keicho Nijimura, Yukako is a Stand User who freely manipulates her hair through Love Deluxe.