On one of his first days at Yamaku, a special academy for the disabled, Hisao Nakai accidentally meets a Russian girl in a wheelchair. Sonia, the stranger's name, catches Hisao's attention, and he decides to get to know her better. At first, all his attempts to talk to her break down against an icy wall: Sonya is short-tempered, apathetic and indifferent to almost everything. But one day this wall begins to thaw.... Who is Sonia? What secrets hide the past of this mysterious girl? And what lies