Shuuchizuma Chijoku Densha ~M no Kakusei ni Tomadoi Ochiru Kouhai no Ane-san Nyoubou~

30-year-old Keiji Joujima is a prolific molester who habitually targets women in the train. He sets his sights on Reika, a 29-year old housewife whose six-year-long marriage is beginning to go stale. Reika's husband is completely unenthusiastic about sex and she is beginning to worry that she is no longer attractive, but when she meets Keiji, her masochistic and exhibitionist tendencies begin to emerge.