Satomi Kaizuka serves as a uniformed officer in the Tokyo Metropolitan Police Department's Criminal Investigation Bureau. She performs clerical duties under Superintendent Ryoko Yakushiji, primarily involving the sorting and organization of materials within police reference rooms, also termed archives in some translations.

During the documented FILE06 incident ("Made in Kasumigaseki"), Kaizuka was working in a reference room alongside fellow officers Mario Abe and Inspector Maruoka. An unusual rumbling and falling books initially led her to believe an earthquake was occurring. This disturbance, causing Kaizuka visible alarm, was later identified as the result of a giant salamander moving through underground tunnels beneath government buildings.

Kaizuka has dark brown hair and brown eyes. She is 21 years old.