The old man is having sex with his son's wife.

It's been a few months since my beautiful daughter-in-law Akari moved in with my father-in-law, Shigeru. Taking advantage of the trial living time, I started trying to get pregnant, something I had been struggling with for a long time without much success. After a examination at a fertility clinic, it was discovered that the husband had sperm problems. One day, the husband was scheduled for a business trip for 2 nights and 3 days. Akari and Shigeru were alone under the same roof.