Seiji was born as the second son of three brothers. From the perspective of her mother, Reika, she had the impression that she was an easy-going child, but... One spring, my older brother got a job and lived alone, while my younger brother entered a boarding school. My father moved away from home and his life changed in a hurry, and Seiji and Reika started living with their mother and child. The lively house suddenly becomes quiet, and Reika feels a sense of loss... Seeing his mother like this, Seiji feels frustrated and empty, and tries to regain his mother's love, which he could not monopolize until now.