Akiuki, a high school student from the Southern Territory, lives quietly with his mother while war burns between the northern and southern continents. On one morning, he rushes out late for school, stops at his father’s clinic to deliver lunch, and barely catches the bus. Frucci is annoyed because he loses a bet to Haru, but Akiuki has no time to celebrate. At the bus line, he notices Azure, a strange student without the proper armband, struggling to board. That small detail becomes the first sign that this trip is far from ordinary.