Young Lady Detectives: Heart Beat! (1987)

Two cute amateur sleuths get in over their heads (and between the sheets) in the Japanese "pink" movie Young Lady Detectives: Heart Beat! (1987). Misao (Michiko Nishiwaki) and her roommate Harumi (Yuko Mizushima) are recent college grads who open a detective agency to avoid having to move back home with their parents. The agency is just a front, but their first client is very real, and soon Misao and Harumi are plunged into a dangerous world of drugs, blackmail, and live sex shows. Wait, did somebody say "live sex shows?" Yup, and there's a SKINtillating nude photo session featuring Michiko's bare boobs, too. Heart Beat! will make you beat hard.