"Sperm donation" is the act of ordinary men donating sperm to couples struggling to conceive. [Couple 1] A couple in their second year of marriage. The husband is controlling and anxious, and his wife, Tsumugi, is a little tired of him. The husband is reluctant to accept a donor who seems like a playboy, but at his wife's insistence, they start with a massage to boost her basal metabolic rate... [Couple 2] A couple in their second year of marriage. Reina, the wife, wants the timing method, which has the highest pregnancy rate. She persuades her husband to have direct sex with the donor, but the preparatory massage ignites her carnal desire. She shakes her large breasts and sways her hips, her sexual desire bottomless... [Couple 3] A couple in their third year of marriage. "Wouldn't you mind if I had sex with another man?" The husband wants a child, so he wants to use the timing method, but his wife, Aya, is opposed, refusing to have sex with someone else. At the husband's insistence, they decide to start with a massage to boost her basal metabolic rate, but... [Fourth Couple] A couple in their fourth year of marriage. Ichika, the wife, is growing increasingly anxious about having direct sexual intercourse with a donor, but she can't resist the strong persuasion of her husband, who desperately wants a sperm donor, and so she decides to undergo the timing method. At first, she reluctantly accepts, but gradually she finds herself at the mercy of this stranger's penis... and every time it penetrates deep inside her, she climaxes multiple times... This four-hour video features four beautiful wives who are only meant to donate sperm, but end up indulging in carnal desires.