Masaaki's father disappeared soon after he was born, and Reiko raised him on her own. Seeing his mother working so hard for her son, the son felt a strong sense of gratitude. That gratitude grew day by day, and before long, Masaaki began to see Reiko as a woman. Meanwhile, when Masaaki graduated from university, Reiko also felt a void in Kokoro. This was due to the loneliness of not having a loved one anymore. The two were in love with each other.