Miyako is Maron and Chiaki's classmate who lives across the hall from Maron. Miyako is the child of parents who are detectives, and thus Miyako is always trying to catch Jeanne. She says the reason of catching Jeanne is to prove Maron's innocence because half a month before the beginning of the series people in their class were saying Maron looks and talks just like Jeanne. In the anime, Miyako does not know that Maron is really Jeanne she tries so hard with tricks and plots that are rather dangerous to Jeanne just to catch her. She causes a lot of trouble for Jeanne and her mission. Miyako does not know about Maron's true self until the end. However, in the manga it is different. Miyako says that she knew Maron was Jeanne from the beginning, and saying that the reason she was in Jeanne cases was if Maron was caught, she could just say it was a mistake. She is madly in love with Chiaki, but gives up on him since he is more interested in Maron. She is stubborn and is exactly like Maron. She usually gets mad every time Jeanne escapes. After Yamato tells her about his feelings for her near the ending, she gets mad, thinking he's playing a sick joke, and neglects him. However, in the manga, she married Yamato Minazuki and has a son named Shinji (the reborn form of Access).

(Source: Wikipedia)