Keiji, the second son of a three-brother family, has always been quiet and reserved in the eyes of his mother, Rin. One spring, his older brother begins living alone after landing a job, while his younger brother enrolls in a boarding school. As a result, their father takes a job transfer and moves out for work, leaving the house suddenly quiet and empty. Rin feels a deep loneliness from the change, quietly carrying a sense of isolation within. Witnessing his mother's solitude, Keiji regrets having previously focused all his attention on his brothers, and begins to draw his mother's affection toward himself alone, seeking to fill the emotional void between them. Through small daily moments and quiet conversations, their bond gradually deepens. This story portrays the growing, intimate connection between a mother and her son in the stillness of their now-silent home.