Five years after getting married, Mio was feeling anxious about not being able to conceive a child. Her relationship with her husband was good, and they had sex properly timed with her ovulation days. However, she could not get pregnant. Then one day, Mio learned that her father-in-law had six children. When she heard this, Mio came up with a forbidden act. Common sense told her it was wrong... but desperate for a child, Mio asked her father-in-law for a sperm donation. Wanting an heir, the father-in-law decided to respond to Mio's outrageous request in a business-like manner. Even as they told themselves it was just a business arrangement, pleasure overflowed. Mio and her father-in-law desperately resisted that pleasure. And the decision they finally made was...