Having become a university student, son Hiroaki remained dependent on his mother, Sayoko, with no friends or romantic partners of his own. As a single mother, Sayoko had always doted on Hiroaki and raised him indulgently. Now in his third year, Hiroaki was nearing graduation, and Sayoko began wishing for his independence, plotting to create a turning point for him. One day, she won an inn stay voucher in a local shopping district raffle. Hoping this trip might spark a change in Hiroaki, Sayoko decided to take him on a hot spring getaway.