New name, no past. This is a tradition long held at Ulmass Military Academy. Shuttered during a bloody civil war, the academy is ready to open it's doors to the next generation of officers. Plagued by a past he desperately whishes to escape, the student known as Oak finds himself a part of Class Four, along with seven other students. Their young instructor, the apathetic Ring, eagerly volunteers his students for monthly expeditions to hunt dangerous animals for money. As they grow closer, and begin to uncover a truth buried in their pasts, Class Four must risk life and limb to protect not just those that hired them, but each other as well.