This summer, Erika lost her husband in a traffic accident and began living alone with her stepson, Shoichi. Though unrelated by blood, both harbored hidden feelings for each other. Shoichi struggled to suppress his growing desire and decided to leave home, but right before his departure, his father passed away from illness. Since then, he became increasingly reclusive. One day, Erika invited him on a hot spring trip, and without hesitation, he agreed. The warm, peaceful time together at the soothing springs gradually began to change his heart.