Three years into their marriage, Junichi and Miki are actively trying for a baby. To maximize their chances during Miki's fertile window, Junichi abstains for an entire month before her ovulation day. Miki's older sister Maria lives in the same building and cannot conceive because her husband has ED. Determined to have a child before her younger sister, Maria waits until the couple's planned baby-making night approaches, then arrives in revealing clothes with her huge braless breasts and nipples showing. She seduces Junichi and drains him of every drop he saved for his wife.