Reina, a daughter-in-law who is being pressured by her mother-in-law to give birth to a grandchild, has been ordered to refrain from having sex until a hot spring trip in a month in order to conceive. However, on the day of the trip, her husband refuses to have sex with her. Meanwhile, her father-in-law tries to embrace his wife, but is also refused. The two, with their sexual desires at their wits' end, head to the hot spring to calm their bodies. Then, by chance, the father-in-law witnesses Reina's seductive bathing figure and is unable to suppress his desire...