Warin Radboud, a young soldier enlisted in the Royal Army of the Kingdom of Berk (KOB), dreams of defeating the Union of Mankind (UOM) and bringing peace to the world. Serving in the North Department, Warin and his lifelong friends embark on various missions. However, a particular envelope leads him to the Central, the headquarters of the Royal Army, where a mysterious key found by his friend, Bernat Roser, catapults his life into a realm of dark truths...