The streets of Tokyo swarm below fifteen-year-old Copper as he gazes out into the city of his childhood. Struck by the thought of the infinite people whose lives play out alongside his own, he begins to wonder, how do you live? Considering life's biggest questions for the first time after the death of his father, Copper turns to his dear uncle for heart-warming wisdom. As the old man guides the boy on a journey of philosophical discovery, a timeless tale unfolds, offering a poignant reflection on what it means to be human. But when Copper betrays one of his new friends, how will he ask for forgiveness — and how can he forgive himself?