After a prolonged era of peace following centuries of conflict, Toru Acura, a former saboteur, finds himself adrift without purpose. His life takes a drastic turn when he rescues a enigmatic wizard named Chaika Trabant, who carries a mysterious coffin. Tasked with aiding Chaika on a perilous expedition, Toru and his sister Akari embark on an adventure that shatters their monotonous existence, plunging them into a world of danger and intrigue.