Amid overpopulation, dwindling resources, and civil unrest, six major corporations launch a coordinated global uprising known as the National Dismantlement War, which overthrows all countries on Earth and ushers in a new world order of corporate-enforced peace: the Pax Economica. To efficiently redistribute resources, people are relocated into oppressively managed settlements called colonies and forced into hard labor. However, a technological gap opens between the corporations with the advent of Beryil technology, which utilizes potent and hazardous Beryil Particles as energy. Beryil technology is instrumental in the creation of ARSENAL; a 12 meter tall humanoid multi-purpose combat mechs capable of flight using advanved jet engine. And the corporations begin waging a shadow war among themselves for control of it. Five years into the Pax Economica, the colony of Aeolia enters a financial crisis. Aeolia is one of a handful of colonies that enjoys autonomy from the corporations, but this was solely due to the wealth of the late Professor Rochelieu, a leading ARSENAL engineer. Upon Rochelieu's death, most of his staff defected to the corporate research colony Elysia, severing Aeolia's income stream, and leadership of the colony fell to Maximilian Duron, one of Rochelieu's researchers. To keep Anatolia funded, Maximilian modifies a crippled veteran mech pilot into an Augmented Human, gives him an ARSENAL, and sells his services as a mercenary to corporations that lack their own ARSENALs. Cassandra Rochelieu, the professor's granddaughter, agrees to act as the pilot's operator, after she has no other choice. She is also the one who found the crippled veteran mech pilot, who was dying on a fallen mech during the National Dismantlement War. This modified pilot is the silent main character, who is also referred to as "Aeolia's Mercenary". At first, Aeolia's Mercenary is only hired to counter rebel attacks, but he steps into the spotlight by defeating the rebel group Kazumba Liberation Front (KLF). He then receives more lucrative and dangerous jobs fighting in skirmishes between rival companies until he is tasked by Global Aristocrats (GA), one of the six major corporations, with assaulting a GA subsidiary that plans to secede. The mission is successful, but provokes another company named ALTEX into declaring war on GA. This gives the six major corporations an excuse to openly break the Pax Economica, instigating the Corporation War. ALTEX gains the backing of the Boris and Federik Foundation (BFF), and Ensmont Science Technology, while GA forges an alliance with Morgana Millenium and Atmosmeccanica. Throughout the enormously destructive conflict that ensues, the reputation of Aeolia's Mercenary grows as he takes on missions for the GA coalition and eliminates every other notable mercenary throught out those missions. Notably, he assassinates BFF's entire leadership by sinking their seaborne headquarters, eliminates the strongest mercenary: Duvrion the Hero of National Dismantlement War and his legendary squad "Justiziar", protects Aeolia from a retaliatory strike by an ALTEX-developed superweapon, and leads critical operations against the increasingly desperate Esmont Science Technology. The conflict culminates in the dissolution of both Esmont Science Technology and ALTEX; at the same time that Esmont Science Technology's headquarters is destroyed by Aeolia's Mercenary, ALTEX's headquarters is coincidentally destroyed by another mercenary from Elysia named Ellion, a childhood friend of Cassandra. With the Corporation War over, Aeolia finds itself with a comfortable amount of funds. Unfortunately, Ellion carries out a surprise attack on the colony in a prototype ARSENAL and razes most of it to the ground before he is vanquished. Cassandra and Aeolia's Mercenary then decide to leave Aeolia, with Maximilian unable and unwilling to persuade them to stay.