A corporation that significantly outperforms the Three Major Corporations in all fields and is the sole possessor of psionic technology. Having inherited all the technology of the Old Civilization, they are morally and culturally mature. Unlike the Three Major Corporations, they are not arrogant but are instead exceptionally sincere. They require combat forces to counter space pirates and hostile biological entities. Transactions with this company are limited to a select few high-tier A-Rank mercenaries and above. After completing several requests and earning their trust, they will pay rewards in U and allow the purchase of their products.

Specializes in energy-based systems. They despise the Caucasus Foundation. They claim to be at the cutting edge of technology, and their products are uniformly expensive. They own a subsidiary called Mellow Co., which specializes in control systems such as FCS (Fire Control Systems).

Specializes in live-ammunition weaponry. They despise the Seirei Public Corporation. Unlike other major corporations, they adopt a high-volume, low-margin strategy; their products are very cheap, but the quality is commensurate with the price. They are the go-to corporation for poor mercenaries. They have many subsidiaries, centered around Gloss Co., which specializes in AI automation.

A corporation specializing in steel and heavy materials. They despise Highlander. It is a dangerous company where spiritualism and "guts" mentalities prevail, but their technology is the real deal. Not a day goes by without their name appearing on large-scale weaponry or structures, ranging from combat to daily life. They own Pillow Co., which is strong in frames and propellants, as a subsidiary.

An up-and-coming company specializing in biomechanics. There are persistent rumors that they must have some powerful backing, as they have not been crushed despite being targeted by the Three Major Corporations. They are a rare company that places high value on mercenaries.

A massive platform that collectively handles mercenary requests, resupply, maintenance, sales, purchasing, and more. It is fundamentally an ally to mercenaries. Since requests are issued by consuming money pre-deposited into the system, there is no risk of non-payment. Maintaining absolute neutrality, the system lists everything from ruin exploration and relic collection to underground requests like attacking corporations/colonies or assassinations. Mercenaries are categorized from S-Rank to F-Rank in a ranking system. The capacity increases tenfold at each tier: S has 3 people, A has 10, B has 100, and so on. The lowest rank is F; anything below that is considered Unranked. Beginners start as Unranked. More than half of all mercenaries are Unranked and remain so for their entire lives; therefore, even the lowest rank is a subject of respect. Legitimate corporate requests have rank restrictions, and most cannot be accepted unless the mercenary is F-Rank or higher. Private nominations also exist. It is common for mercenaries to end up killing each other due to double-booking. The system is completely automated in all fields; no humans are present. S-Rank mercenaries are monsters capable of turning the tide of war single-handedly, and even corporations cannot easily touch them. From high-tier C-Rank, mercenaries begin to operate large-scale weaponry, significantly increasing the power level and difficulty of requests. Ranks are determined by the number of completed requests and the defeat of other mercenaries. Ranking matches in simulations are held periodically, causing ranks to fluctuate. There are nearly twice as many Unranked mercenaries as there are Ranked ones. Some mercenaries form clans to tackle requests in groups, while others work solo.