Haruka Luciela is an investigator for the Department of Anomalous Crimes Chemistry Division at the International Anomalous Tactics Organization (IATO), which tracks paranormal crimes linked to "gods" and higher dimensions. She investigates the extradimensional entities called "Nights," gathering intelligence on their activities and motives.

Assigned to assist the Kamaya City police department, she collaborates directly with Shingo Sumeragi's investigative unit. Her methods prioritize obtaining leads by any means necessary, leading her to deliberately establish close contact with Matoi Sumeragi and Yuma Kusanagi after deducing Matoi's connection to Nights exorcism. Despite her highly secretive approach, she shows patience and kindness towards Matoi and her friends, often adopting a protective stance.

She has distinctive multicolored hair and green eyes. She wears an extremely low-cut top that frequently draws attention, contributing to her portrayal as a focal point of visual interest, and rarely appears without her signature cool shades. Her demeanor remains professional and largely disinterested in romantic advances, despite attention from male colleagues like Hideo Tezuka.

She is French, with a birthday on July 31; her specific age is not documented.