Mahiro, the daughter-in-law pressured by her mother-in-law to have a grandchild soon, finds out that the family is going on a hot spring trip. However, for the sake of having a child, she is ordered to abstain from sex for a month leading up to the trip. On the day of the trip, her husband surprisingly refuses to have sex with her. Meanwhile, her father-in-law also tries to approach his wife but is similarly rejected. The two, overwhelmed by their sexual desires, head to the hot spring to calm their bodies, but the father-in-law accidentally sees Mahiro bathing and cannot control his lust…
