Tantei monogatari: Amaku midarana wana

探偵物語 甘く淫らな罠 (original title)

Synopsis

Amon, who runs a private investigation agency, receives a request from his ex-girlfriend Kumi to investigate her husband's infidelity. Kumi's husband is Amon's best friend, detective Kagawa. As the investigation progresses, the surprising truth surrounding a vicious fraud case comes to light...