Sperm donation...— An unusual act where ordinary men provide sperm for couples struggling with fertility. [First Couple] A married couple for two years. The husband is possessive and anxious, while his wife, Tsumugi, seems slightly fatigued. Though the husband objects to the flirtatious male donor, he reluctantly agrees to an unprecedented approach—starting with metabolism-boosting massage—due to his wife's strong insistence. [Second Couple] Another couple married for two years. The wife, Reina, desires the most effective timed intercourse method for pregnancy. After convincing her husband, they proceed to direct sexual intercourse with the donor. However, the preparatory massage awakens her lust, and her big tits sway wildly as she passionately grinds her hips, unable to stop. [Third Couple] Married for three years. The husband, eager for a donor, asks his wife, Aya, "Wouldn't you care if I had another man?"—pushing for timed intercourse. His wife opposes sex with another man, but due to her husband's strong wishes, they enter a strange situation, starting tentatively with metabolism-boosting massage. [Fourth Couple] Married four years. The wife, Ichika, feels uneasy about having sex with the donor, but unable to refuse her husband's desperate desire for a donor, she agrees to timed intercourse. Initially reluctant, she gradually becomes overwhelmed by the stranger's cock, reaching climax repeatedly as he thrusts deep inside her. Four beautiful wives immersed in carnal desire, captured over four hours under the name of sperm donation.