A typical high schooler with a charismatic and helpful nature, he lives with his mother who has separated from his father due to marriage problems. Because of this separation, Akiyuki is expected to take a prepared lunch to his father every morning, as well as keep the two's relationship running smoothly. He has two close friends, Haru and Furuichi. One day, he wakes up late and rushes to deliver his father's lunch, which ends up with him barely able to catch the schoolbus. He notices a white haired girl (Nazuna) at the back of the line and lacking the armband needed to actually get on the bus, so he obligingly gives it to her. As they arrive at the school, Nazuna presses a device and blows up the partially filled bus, resulting in a blinding blue explosions that rips apart the vehicle and throws other students on to the ground. In the light from the explosion, a strange light rises from the destruction and disperses into Akiyuki's arm, producing a strange blue gem-like object, however it's forgotten as Akiyuki notices Nazuna wounded on the bus. He rushes to help her, leading her to reveal that she was the bomber. She then presses Akiyuki's forehead, which materializes a red gem-like object, and she faints. Akiyuki's arm then transforms, covering his body in a strange white liquid and turning him into a white creature called Xam'd.