Ikuko Miyaura, mother to the protagonist, relocates with her daughter to Shio Island after her husband Kazuo’s death, seeking solace in her childhood home and nearby relatives. Grief pervades her actions, though she steadfastly masks it to shield her daughter. Enrolling in nursing classes becomes both a pragmatic pursuit of stability and an escape, inadvertently isolating her daughter, who perceives it as dismissal of Kazuo’s memory. Tensions erupt when her daughter confronts her, accusing Ikuko of erasing the past—a clash that drives Ikuko deeper into silent anguish.

A lifelong asthma condition, aggravated by stress, peaks during a storm-fueled argument and frantic search for her missing daughter, triggering a near-fatal attack. This crisis fractures her emotional armor, compelling her to confront suppressed sorrow and the toll of her stoicism. The ordeal sparks fragile reconciliation, as both acknowledge their shared loss.

Her dynamic with Koichi, a postman and childhood friend, hints at a complex past. His unspoken affection lingers unaddressed, overshadowed by her focus on her daughter and unresolved grief. A shattered mirror—Kazuo’s keepsake—mirrors her fractured psyche, its accidental breakage paralleling her crumbling resolve.

Ikuko’s journey shifts from restrained sorrow toward tentative vulnerability. Discovering Kazuo’s unfinished letter, which reveals his pride in their daughter, becomes pivotal. Its words soften her defenses, allowing acceptance of the past and tentative steps toward rebuilding bonds in their fragile new beginning.