Reno, a daughter-in-law, is pressured by her mother-in-law to give birth to a grandchild. One day, the whole family decides to go on a trip to a hot spring. However, in order to conceive, her mother-in-law orders her to abstain from sex for one month until the trip. On the day of the trip, Reno is refused sex by her husband. Meanwhile, her father-in-law tries to embrace his wife, but is also refused. The two, with their sexual desires at their disposal, head to a hot spring to calm their bodies. Then, by chance, the father-in-law witnesses Reno taking a bath and cannot suppress his desire...