Above, a poster for Tsumatachi no Gogo Wa Yori: Kano no Ori, which is quite a mouthful that in English was simplified to Cage of Lust: Wives’ Afternoon. The movie was adapted from a novel by Hiroko Nakayama and starred Junko Miyashita in a tale of infidelity, deception, lesbianism, etc. It’s a typical Nikkatsu Studios effort, quick and easy at 72 minutes from end to end. It premiered in Japan today in 1976.
When they say they're getting together to enjoy some girl time it may not be as innocent as it sounds.