Miyu Mido is the older sister of Miko Mido, the main protagonist of the La Blue Girl series. She works as a drama actress, leading a normal life apart from her family’s secret ninja heritage. In the original OVA story, Miyu is kidnapped by demons from the Shikima world who seek the signet case that controls the Shikima, forcing her younger sister Miko to rescue her. During the later series La Blue Girl Returns, Miyu is again targeted by the butterfly-like Mahoroba clan, who attempt to enslave her and Miko in order to steal the seal case. Miyu’s role in the story is primarily that of a civilian victim whose endangerment motivates Miko’s actions, though she does accompany Miko and the ninja Nin-Nin into the Shikima world at times. She has no known ninja training or supernatural abilities, and she relies on her sister for protection. Over the course of the series, Miyu does not undergo significant personal development, remaining a relatively ordinary person caught up in extraordinary events. Her most defining relationship is with Miko, whom she looks to for rescue and support.