Koujirou Shindou, a government official and excellent negotiator with a well-earned reputation, is calm and logical. A enormous cube appears as he is leaving on a business trip, and his jet is transported unharmed inside the strange, unbreakable structure. Shindou encounters an extraterrestrial creature known as Yaha-kui zaShunina, who materializes in the guise of a human man, while Japanese officials strive to discover the cube's features and origins. He tells Shindou that the passengers are safe and asks for assistance in discussions with the human world.