Miyako Terada is a seventeen-year-old second-year student at Maijima High School, enrolled in Class 2-B. She is a close friend of Ayumi Takahara and Chihiro Kosaka, and the three are often seen spending time together. Miyako has long black hair and freckles on her cheeks. She is a member of the school's track-and-field club, with a specialty in the 400-meter dash.

Miyako is described as outgoing and smart. She is also notably kind and considerate, as she refrains from calling Keima Katsuragi by the nickname Otamegane, unlike many of her other classmates. Throughout the series, she appears regularly as a supporting character but is never possessed by a runaway spirit, meaning she does not become a direct target of Keima's conquests.

Her role in the story becomes more prominent after the Chihiro Arc when she joins Chihiro's band, 2-B Pencils, as the keyboardist. Miyako is responsible for playing a KORG X50 synthesizer in the group. Her involvement in the band is central to the events of the OVA The World God Only Knows: Four Girls and an Idol, where she, along with Chihiro and Ayumi, seeks help from Keima to improve their musical performance. Through this experience, she develops a closer bond with her friends and contributes to the band's growth.

Miyako's motivations are rooted in her loyalty to her friends and her enjoyment of shared activities, whether in athletics or music. Her abilities include athleticism in track and field, particularly in sprinting, and musical talent on the keyboard. While she does not undergo major personal transformation or a romantic subplot, her steady presence and positive attitude provide a grounding element within the group.