Yuya's parents are separated, his mother is a nurse and has signed up for a well-paying job during the summer vacation. For the boy's good. During this time, Yuya visits his grandparents in Kagawa, the birthplace of his mother. Every night Yuya is plagued by nightmares in which he is chased by a blue lion costume. His grandfather knows more about it - he painstakingly handcrafts these costumes and tirelessly fights against the decay of an ancient tradition - the Kagawa lion dance.