Mature Swap: Like a Beast (1994)

Original title: 熟女スワップ 獣のように

Chitose, who runs a long-established Japanese sweets shop, was forced to marry a man who assaulted her when she was a university student, but he died after allowing Chitose's body to mature. She now entrusts her shop to her manager, Aikawa, and adopts Mayumi, who used to be her bunny girl, and indulges in homosexual pleasure. One day, Chitose reunites with her ex-girlfriend, Yoshida, and plans an orgy with him, his wife, Yuri, and Mayumi's boyfriend, Junji...