Iscodaya Kousa, a moody, black-hair, and red-eyed sixteen-year-old, studying in Japan as an exchange student. A boy who is also the Prince of a Kingdom in another dimension. Tasked to find information about his newly discovered surroundings, he is accompanied by his servant and personal sword, Kaus Irom.

But in their studies, the young Prince meets a girl in this land, Kei Inoue. With her, Iscodaya not only discovers more of Earth, but also discovers a lot more about himself.