Six months after the earthquake disaster in Sendai City, Kazumasa Nakagaki is a young man who has lost his job. He encounters a dog named Tamon on its dog tag, who lost its owner in the earthquake disaster. Kazumasa decides to take Tamon in, and the dog becomes attached to him and his family, but Tamon always seems concerned about something in the south direction. One day, while Kazumasa is involved in a dangerous incident, Tamon disappears. Later, in Shiga, Tamon is with Miwa Sugai, who has a sad secret. Kazumasa reunites with Tamon, and they start a new life together. Nevertheless, Tamon heads south because Tamon has a promise it wants to keep to a boy.