Wandering in the vastness of space, is the Sky Drifter; an academy reserved for the best students in the known universe. Seven is just such a student. Gifted in strategy and Sphere, he lives happily on-board with his friends Iris and Pi, taking on his rival, visiting planets for exploration and competition. Everything is the way he likes it, until he sees a mysterious girl in a red coat, who will reveal to him a secret that will bring everything he thought he knew crashing down around him.