Naomi is a rich university student about to leave on a trip to America.
Things get complicated when Shuichi's ex-wife is suspected in the murder of a love hotel manager.
Naomi and Shuichi join up to investigate the murder which may involve yakuza gangsters.
Detective Story, director Negishi's third mainstream film, was based on a novel by mystery writer Jirō Akagawa.
[2] Lead actor Yūsaku Matsuda also played the role of a detective (Shunsaku Kudo) in the 1979-1980 TV series Tantei Monogatari (Detective Story) but the film is unrelated to the TV series.