Shion Ogura is a 15-year-old female student at Sakuragaoka High School. She stands 154 cm tall, has long black hair, blue eyes, and wears circular glasses. Her birthday is December 14. She lives in the attic above the Yoshida household.

A member of the school's Black Magic Research Club, Shion pursues occult studies with strong enthusiasm. She possesses above-average deduction skills and rapid reading abilities, focusing her research on phenomena like magical girls and demons. Ethical concerns often take a backseat in her pursuits. She maintains friendships with Yuko Yoshida and Anri Sata.

Shion's family background connects to demonic lore. Her name derives from Gusion, a demon linked to knowledge and time. Gusion identifies Shion as "a fragment of myself I left behind, the last page of my life's story," indicating she is a descendant or spiritual fragment of this entity. No notable supernatural abilities manifest beyond her intellectual traits.

Within the club, Shion actively investigates Yuko Yoshida's demon heritage. She collects extensive information on the Dark Clan and shows particular fascination with Yuko's demonic traits, sometimes employing ethically questionable methods that reflect her prioritization of knowledge over moral boundaries. Her activities document interactions between magical beings in her environment.

Shion's character development reveals increased involvement in supernatural occurrences alongside club members, with her analytical skills becoming more applied in practical situations involving magical phenomena. Her attic residence above the Yoshida home facilitates closer observation of demon-related activities. Relationships with classmates persist through collaborative research efforts and school activities.