She is a pretty detective with the Tokyo police, who often uses the City Hunter team to do her job for her. She keeps promising to pay back Ryo with "mokkori" (sex), but always manages to get out of it. Despite her deceptive tendencies, she and Ryo have a considerable history together, and was in a love triangle with Ryo and Hideyuki Makimura.
Saeko's father is the chief of police, so she has some leeway in how she does her job. But off the job, her father puts the pressure on her to get married.
In the spin-off Angel Heart, Saeko was the chief of police who used to date Hideyuki Makimura and was implied to be waiting for Hideyuki's proposal. In later chapters, Saeko's hidden dream was to have a normal family with Ryo, implying her shift in romantic interest.
Related anime:City Hunter TV, 1987
City Hunter 2 TV, 1988
City Hunter 3 TV, 1989
City Hunter: .357 Magnum Movie, 1989
City Hunter: Million Dollar Conspiracy OVA, 1990
City Hunter: Bay City Wars OVA, 1990
City Hunter: Bay City Wars Movie, 1990
City Hunter '91 TV, 1991
City Hunter: The Secret Service TV-Special, 1996
City Hunter: Goodbye My Sweetheart TV-Special, 1997
City Hunter - Death of Evil Ryo Saeba TV-Special, 1999
Angel Heart TV, 2005
Related manga:City Hunter Manga, 1985
Angel Heart Manga, 2001