The Big Ten

With the Shiawase Decision, corporations suddenly gained a massive amount of political power, which they were quick to take advantage of. With political power comes conflict, however, so the early 2000s were marked by corporate warfare that were equal parts destructive and bad for long-term business. As such, the biggest corporations came together to form the Inter-Corporate Court (ICC), a council that would mediate problems between corporations. The original members of the ICC are referred to as the Big Seven, but the constituent members have increased since those initial days, leading to the current Big Ten.

The Big Seven

When corporations gained the power of extraterritoriality, they started conducting themselves the way a nation-state would; increased budgets dedicated to offensive and defensive capabilities and complex diplomatic relationships with their fellow corporations. Tensions rose as each corporation became more and more paranoid of each other, until the tension broke with a declaration of war. Keruba (which would become Renraku) and BMW (which would become Saeder-Krupp) went to war over access to resources in 2010. The brief war saw both sides nearly reduced to rubble, a sign to the other corporations that war was not as good for business as they initially believed. When the following year brought forth the Awakening, and the subsequent worldwide chaos, the corporations realized that they would need to regulate themselves to ensure they weren't impacted by each other's conflicts.
As such, the biggest corporations of the time gathered together to form the Inter-Corporate Court. The Court's initial members were ORO (now Aztechnology), Fuchi Industrial Electronics, Mitsuhama Computer Technologies, Keruba (now Renraku), Ares Industries, BMW (now Saeder-Krupp), and Shiawase Corporation. While the sentiment was there, the initial ICC had little to no actual power, so its rulings were not expected. A war between ORO and Keruba in 2013 proved to the world that the ICC couldn't manage its own members. Political maneuvering was necessary to see the vision of the ICC through.

The New Corporate Court and the Big Eight

The ICC solved their authority problem the same way corporations always solve their problems these days; extreme violence. The war between ORO and Keruba emphasized that rising powers had the ability to challenge even the biggest corporations, so the Big Seven buckled down and started taking the ICC seriously. The began exerting authority over any corporation smaller than themselves, including each other when necessary. Those who didn't take the ICC seriously were assassinated, often in very public and over-the-top manners. This essentially handed the lower corporations an ultimatum; either submit to the ICC, or deal with those who do. 
With their newfound authority, the ICC rebranded itself to just the Corporate Court. In 2023, the Court justices were moved up to the Zurich-Orbital Habitat, alongside which they codified the ranking system used to this day. During this rebranding, one final corporation joined the Court; Yamatetsu Corporation finally had the backing by 2023 to join the Court, though not without some losses. One of the rules codified in those early days was that each member of the Big Seven must always have representation on the Court. As a latecomer, Yamatetsu is not protected by this ruling. 

The Modern Big Ten

Changes to the Court rarely occur, but when they do they tend to happen with extensive fanfare. The first change ocurred with the slow and painful death of Fuchi. Although Fuchi was an original member of the Big Seven, its place on the Court was pushed by its ownership of JRJ International. As such, when Fuchi began floundering its seat was given to Novatech Incorporated, new owner of JRJ. This has put the Court in a somewhat odd position; Fuchi still exists, and could technically return in power, but Novatech holds its biggest assets and currently has the power to be on the Court. As of yet, this situation has not become a problem but the Court still keeps a watchful eye on Fuchi. 
The last two members of the Big Ten are often seen as a shift in the mindset of the Court from pragmatic to opportunistic. Both Cross Applied Technologies and Wuxing, Incorporated are substantially smaller than the rest of the Court corporations, but have shown both prowess and drive. Cross represents a counterpoint to Ares, which had grown too much in the years prior, and Wuxing represents a challenger to the corporations of Japan, most notably Renraku. Unfortuately, allowing the corporations onto the Court muddied the definitions of the ranking system, potentially leading to another major conflict for the Court.