After leaving her abusive husband, Misa lives alone with her son, Taichi. Struggling financially without her husband's support, raising Taichi on her own becomes an immense burden. When Taichi was in middle school, Misa accidentally discovered him masturbating. From that point on, seeking some relief from their suffocating daily life, she grew increasingly close to Taichi, though she never crossed the line into sexual intercourse. One day, she receives a pair of hot spring resort tickets as a gift from a coworker, and decides to take Taichi on their first trip away together.