For mother Tsubaki, her second son Kenji had always been an easy child. But one spring, his older brother got a job and started living alone, and his younger brother entered a boarding school. His father also took a solo work assignment, and life changed completely. The once lively house suddenly fell silent, and Tsubaki felt a sense of loss. Seeing his mother like this, Kenji felt frustration and emptiness over her preoccupation with his brothers. And so, he began to move to monopolize his mother's affection. In their life together as mother and son, the silence transformed their relationship.