Sumire faces constant pressure from her mother-in-law to produce a grandchild. Before a family hot-spring trip, she is ordered to abstain for a month to improve her chances of conceiving, but mechanical sex with her indifferent husband leaves her unsatisfied. Her father-in-law is equally frustrated after his own wife rejects him. Both head to the baths to calm their pent-up desire, where he happens to see Sumire bathing.