Saeko Muranushi is a 39-year-old Japanese exorcist with brownish-grey hair typically secured in a bun and grey eyes, standing 161 cm tall. She possesses psychic abilities, including the capacity to detect and answer questions before they are fully voiced, as demonstrated when she anticipated her daughter's unspoken concern about living arrangements. Her demeanor features minimal facial expressions and a consistently monotone vocal delivery, traits she has passed on to her children. She employs exorcism rituals as her primary method for resolving diverse problems, including interpersonal conflicts.

She harbors a significant fear of medical establishments, stemming particularly from an aversion to needles. Her family consists of her daughter, Sayuri Muranushi, and son, Satoru Muranushi. Sayuri actively dislikes her mother's superstitious practices and reliance on exorcism. Saeko Muranushi's known background is confined to her roles as a mother and exorcist. Her portrayal across official media remains consistent with this initial depiction, showing no significant evolution or expanded history.