Long ago on the planet Earth, Humans and Gens lived together happily. The King of Humans, and the Queen of Gens made peace within both kingdoms. After years of this peace, humans began to fear the powers of the Gens.
Gens had the power to control planets, and most of the solar system. When a new Gen is born, a planet or a unique job is given to them. That process is known as Claiming Gifts, thus meaning the planet or job was considered claimed.
Jobs were given to normal citizens, and were given based off their unique abilities. Jobs can be given to many citizens with common abilities, but planets are different. Unlike jobs, the planets can have only one claimer. That claim is based off abilities that Gen will have, but also off of what special achievement that Gen will make. Gens who claim planets have more power than common citizens, that is because that Gen will be able to control the entire planet, and make changes to it's characteristics if the Gen wants so.
The Humans feared what would happen when Earth was claimed. For years Humans and Gens had ruled peacefully side by side. The Gens had powers while the Humans did not, Gens could easily overpower them. If Earth was claimed then what would happen to Humans? The Humans became hostile, they didn't want Gens to ever become powerful enough to take over the world entirely. The Humans began to think of what would happen without Gens in control. These were just thoughts at first. Gens tried to be peaceful, but soon both kingdoms broke into war by the news of the death of the Queen of Gens.
"With no Queen to lead them, the Gens retreated into a cave far away from humans. Humans took control of the surface, and later forgot the Gens entirely. Gens now live in two kingdoms underground, away from human eyes. Here we can live our lives about the same as we could then, just without the threat of attack. Any questions so far?" Spoke Evelyn, a girl teaching some children about Gen history.
Van and his friend Magus had reincarnated in another world with magic. Tasked to kill the demon lord, they set forth.
Van was granted very rough skills that made life for him in that world a living hell, yet he muscled through.
Magus however, was bestowed with unfair skills. Due to some of said skills, he gained a harem, which in time, included the girlfriend Van made in the world.
After beating the Demon Lord, and after finding out his girlfriend had been stolen from him, he got very upset and so he went to propose to- *reads script* Uh, WHAT?!