Following a devastating earthquake and tsunami, a young man in Japan finds a stray dog outside a convenience store. The dog's tag says "Tamon," a name evocative of the guardian deity of the north. The man decides to keep Tamon, becoming the first in a series of owners on the dog's five-year journey to find his beloved first owner, Hikaru, a boy who has not spoken since the tsunami. An agent of fate, Tamon is a gift to everyone who welcomes him into their life.