Inbō no yoru: Kurikaesu masayume

Original title: 淫暴の夜　繰り返す正夢

Mizuki, born as conjoined twins, works at a hospital, but the director, Sato, takes advantage of her weakness, as she needs artificial dialysis, and makes Mizuki his mistress. However, Sato's wife, Mikayo, discovers his infidelity.