On rain-soaked mornings in Tokyo, fourteen-year-old Shinji Minakawa escapes a home ruled by violence and exhaustion, finding refuge in a forgotten winter garden hidden behind rusted gates. There he meets Hakurage Shizu, a guarded fifteen-year-old living alone among rare blooms cultivated by his late botanist parents. With creditors threatening to seize the dying sanctuary in six months, Hakurage asks Shinji to paint a series of strangely specific childhood scenes to help fund its survival.

But each painting stirs fragmented memories neither kid fully understands—of a storm long ago, of a shared promise, of a tragedy that shattered both their families at once. As the rainy season deepens, their bond grows into something fragile yet unbreakable.

In a garden where winter flowers bloom against reason, Shinji and Hakurage must confront buried grief and the truth that art can revive more than fading petals.