Yoyogi manifests as a supernatural entity encountered at a shrine. He possesses Takane's falsified exam result sheet, marked with the false ranking of 92nd place. Exploiting Takane's frustration, Yoyogi proposes a deceptive bargain, offering the paper in exchange for "something Takane doesn't need," prompting Takane to offer his sister, Tamaki. When Tamaki arrives seeking Takane and their dog, Chris, Yoyogi immediately transforms her into a shining object and swallows her.

Later, Yoyogi agrees to restore Tamaki only if Takane wins a bicycle race against him, using Takane's broken bicycle, positioning himself as the antagonistic force driving the central conflict. Physically, Yoyogi has light blonde hair and lilac eyes. He frequently wears or carries a distinctive cat mask, enhancing his enigmatic presence. He operates from the "Inari House," conducting unusual and often absurd exchange transactions.