Kiala no Senki, or Records of Kiala, is a Sci-Fi game that takes place in the year 2413 AD (or, in the in-game calendar, 25,413 SY). Humanity on Earth has not quite reached outside its own Solar System, though the Sol System is home to a precious material called Carbon Helium that is, quite frankly, very rare outside of the Sol System, at least in our galaxy. A student at an American university had discovered a piece of Carbon Helium while traveling to Antarctica's Southern Pole and discovered that it could be used for ending the problem of energy supplies for at least until the end of the third millennium... from that piece of Carbon Helium alone.
Meanwhile, outside of our Solar System, a huge war was being waged between two factions of an empire as old as the current calendar: the Neon Warriors and the Vanguard. The reason for this war was over politics, as the leaders of the respective armies were the only sons of the previous Emperor, and only men were allowed onto the throne. The war was beginning to cool off after fifty years of fighting, because the leaders were still human (and thus able to get old at the age of 98), and a peace was being brokered between the leaders when an outside party assassinated the leader of the Neon Warriors. He was succeeded by his granddaughter, Kiala Menossi, and her two month old little brother.
The assassin reveals that he works for the Evernun Commandos, a group of terrorists that were long thought dead to the last man, except that they hadn't died off like everyone believed. The assassin also reveals that he was just one of the many warriors that will "free the galaxy of the evil inside" before he gets run through.
Also, remember the Carbon Helium? Apparently the Evernun Commandos were the first to discover the Sol System and start mining the Carbon Helium from the furthest Plutoid from the Sun, meaning they legally have a claim to the Sol System now.
...well, something like that is what I have in mind for the game story, to be honest.