Tsubasa (Kokoro Terada) is a timid elementary school student who lives with his grandmother (Manami Fuji), his father (Yuya Uchida), and his mother (Yoko Matsuda), who has just celebrated her 50th birthday. Tsubasa loves his grandmother very much. Whenever he feels like he is going to fail at something, he goes to his grandmother and asks her to listen to his story. At times like that, Grandma always tells him it's going to be alright. Even when I was bullied at school, my grandmother would help me. Little by little, that kind grandmother would change. She starts asking the same questions over and over again, and she can no longer do the knitting she was so good at. She became "forgetful of things" (dementia). She became angry, withered her beloved plants in the garden, and ate the jam she made for Tsubasa all by herself. Tsubasa became somewhat scared and stopped coming near her. Then one day, Grandma left the house without shoes on and disappeared. Where did she go, grandmother? Before long, Tsubasa learns his grandmother's secret.