Makoto Hayakawa, who is called Shin, is a third-year high-school student about to take entrance exams. He hasn't decided what to take for college yet. Compared to the other kids, Shin is a bit of an oddball. The neighborhood he lives in, M City of Tokyo, has three massive structures called "Reactors".
One day, a mysterious girl crosses his path, and in front of those reactors their fateful first meeting takes place...