After her son, Nobuo, left for university to live alone in Tokyo, mother Miyuki deeply missed him. When she learned he would finally return home for a visit, she made a reservation at a hot spring inn—the same one she once shared with her late husband—so they could spend time together alone. This inn held cherished memories, a special place in Miyuki's heart. As their time together unfolded, Miyuki began to see Nobuo not just as her son, but as a man. Gradually, forbidden feelings stirred within her, giving rise to an illicit love.