Tsubasa Amami's father-in-law, who worked a lot when he was young, is now old and weak and has injuries that make it difficult to walk. Tsubasa, a filial daughter-in-law who always takes good care of him from meals and sleep, one day he tells Tsubasa that he can no longer erect his penis, he feels unwell and is very uncomfortable when he does so, so he wants to ask his daughter-in-law Tsubasa for help. Tsubasa wondered if she should help her father, because that was really not right, this was incestuous, she didn't want to be sorry for her husband.
But unexpectedly, as soon as he chose to help, the father said that he couldn't get an erection now to fuck her like a machine, it was just a spectacular trick...