The day she was kissed by her stepmother, Reiko, who had been taken as a second wife by her workplace superior, found herself surrounded by an unloving husband and a cold stepson, enduring loneliness within her household. One day, invited by her neighborhood friend Lisa to a party, she unexpectedly encounters her stepson. Amid surprise and conflict, the two realize they share similar sorrows and pain, rapidly closing the emotional distance between them. Drawn into a forbidden relationship, they begin to fulfill each other's emotional and physical needs, bonding deeper and stronger through intense kissing and passionate