Six thousand years before Shiro and Sora were even a blink in Disboard's history, warfare consumed the soil, destroying celebrities ripping apart the heavens, and threatening to get rid of the human race. Amid the chaos and devastation, a man named Riku leads humankind. 1 day, at the ruins of the Elf city, he meets Shuvi, a lady exiled"Ex-machina" android who asks him to teach her what this means to own a person heart.