Chie Setouchi is a third-year student at Osafune Girls' Academy, serving as a Toji—a shrine maiden wielding sacred blades against supernatural threats to humanity. Her chosen okatana bears the name Sohayanotsurugi.

Originally from Gifu prefecture, she shares a childhood friendship with Mihono Asakura. Prior to middle school, Chie moved to Okayama prefecture and has attended Osafune ever since.

Calm and observant, Chie typically surveys situations from a measured distance. Yet this reserved demeanor coexists with an almost sisterly protectiveness toward Mihono and a persistent habit of stepping into others' affairs. Her meddling streak stems from a deeply ingrained caring nature, especially toward those closest to her.