One day, a sister-in-law visits a sexless couple. The pure-hearted wife is pointed out for her inability to conceive. Following her sister-in-law's instructions, she begins infertility treatment, and a procedure filled with shame commences. With her sexual sensations stimulated for the first time, obscene training acts draw out Riko's carnal instincts. Before long, Riko transforms into a captive of sex, but...
