In the spring of 1952, 11-year-old Chizuru moves with her family (her father, his new wife, and her new younger brother) to the town of Nochiu in Hokkaido, a place with strong Ainu roots. They plan to live in a spare building on the property of her father's close friend. That friend has a family of his own, which includes twins, Takeshi and Shizuko, who are Chizuru's age.

Ever since Chizuru survived the air raid in Tokyo that killed her mother and older brother, she has been unable to speak and her memories are confused. However, once they began their journey to Nochiu, she has had the same dream every night. She's in a forest, and someone is calling her name. When she meets Shizuko, she is surprised to realize that Shizuko is the one calling to her in her dreams. Why is Shizuko calling for her, and what are the secrets she seems meant to learn?