Seigo and Miki, in their second year of marriage, were timing intercourse with Seigo's ejaculation to coincide with Miki's most fertile period around ovulation. They had abstained from sex for a month to build up his sperm count. Miki's sister Una, who lived nearby, also wanted children but was in a sexless state due to her husband's erectile dysfunction and his busy work schedule… Una, wanting to get pregnant before her younger sister, visited Seigo on the day her sister and brother-in-law were planning to conceive. She wore no bra, with her nipples visible, seduced Seigo, and took all the sperm he had saved up…
