In a universe where Earth is nothing but a distant memory, humanity's last refuge is space stations threatened by ruthless black-eyed creatures called Onyxes. After a brutal encounter with one of them, young orphan Kazuo vows to turn his fear into strength. Determined to become Hunter, an elite warrior from Adamas Academy, Kazuo embarks on a dangerous journey to protect humanity and prove that he's not just a survivor - he's a hero in the making.