The story is set in a world with a continent split down the middle by a mountain range and a vast river. The eastern side is known as Roxche, and the western side is Sou Beil. The two sides have been at war for the past 130 years, though an armistice has been in effect for the past ten years. Wil, a young man from Roxche who enjoys reading books and has a photographic memory, is spending a leisurely summer vacation at his school's dormitory when his old friend Allison, a young girl his age who is now an Air Force pilot, arrives in a biplane to greet him after not seeing him for six months…