Yoyoko Ohtsuki (大おお槻つき ヨヨコ, Ōtsuki Yoyoko) is a supporting character from Bocchi the Rock! manga and anime series. She is in charge of the vocal and guitar of the band SIDEROS and is also its leader. She always looked up to Kikuri Hiroi and considers Kessoku Band as her band rival, and especially its lead guitarist Hitori Gotoh as her personal rival.

Yoyoko has brown hair which is dip-dyed red and tied in pigtails. Her eyes are light red in color. She wears a beret and a black choker.