In the year 2100 and located on the planet Celar, humans have created a dome and a military corps called the Guard to safeguard the last preservation of the human race. A girl living on the fringes of the Guard, and a fan of street racing named Arden, who allies herself with a deserter from the Guard, accidentally becomes the key to confronting SYFA, a powerful A.I. that will seek to subjugate humans to mechanical transhumanism as the emergence of a superior race, but things will get even more complicated when they will face their greatest threat with the appearance of a mysterious space mercenary that matches an ancient urban legend of a being that was about to completely extinguish the human race in the past.