"Sperm donation" is the act of ordinary men donating sperm to couples who are struggling to get pregnant. [First couple] A couple in their second year of marriage. "There's quite a big age gap, so trying to get pregnant itself is difficult." The wife, Yui, says this, and her elderly husband quietly nods. The two are married despite their age gap, but they have not been blessed with children, so they hope for sperm donation. Later, they try the timing method, which has a high pregnancy rate... [Second couple] A couple in their seventh year of marriage. Himeno, the wife, worries that her husband's male infertility is to blame, and her husband. Given her age, Himeno wants to get pregnant quickly, so she tries direct sexual intercourse with the donor, but the preparatory massage ignites her carnal desires. Eventually, she asks for sex many times, and the neat and beautiful wife suddenly changes into a lewd woman... [Third couple] A couple in their fourth year of marriage. Mai, the wife, convinces her husband to have direct sexual intercourse with the donor because "it's less taxing on the body," but her sweet voice rings out as she falls into serious sex. [Fourth couple] A couple in their second year of marriage. Sana came all the way from Miyazaki this time, and after discussing it with her husband, she decides to have direct sexual intercourse with the donor, saying "we've come all this way..." She writhes in agony as the intense pleasure washes over her every time she moves her hips. ...This four-hour video features four beautiful wives who were meant to only donate sperm, but end up drowning in carnal desires.