The Billionaire's Kept Woman - Chapter 21 - Déjà Vu

Meet Sora and Shiro, a brother and sister who are loser shut-ins by normal standards. But these siblings don’t play by the rules of the “crappy game” that is average society. In the world of gaming, this genius pair reigns supreme, their invincible avatar so famous that it’s the stuff of urban legend. So when a young boy calling himself God summons the siblings to a fantastic alternate world where war is forbidden and all conflicts–even those involving national borders–are decided by the outcome of games, Sora and Shiro have pretty much hit the jackpot. But they soon learn that in this world, humanity, cornered and outnumbered by other species, survives within the confines of one city. Will Sora and Shiro, two failures at life, turn out to be the saviors of mankind? Let the games begin…

15 years ago the world discovered magic as well as mythical beings (basically beings from various legends) in another dimension. Humankind learned to summon these dangerous mythical beings and use their power to great effect. Seven countries formed contracts with these “mythical beings” and gained their allegiance as a result. The mythical beings will choose their summoners on their 14th birthday and give them a stigma. Schools have been set up to train summoners and magical swordsman (basically bodyguards that give the summoners time to cast their spell) as a result.

15 years later after the finding of magic Kazuki Hayashizaki is chosen as a summoner and given a stigma to indicate that. This is surprising since males aren’t chosen as summoners due to their low amount of mana compared to females. As the first male to be a summoner Kazuki is under a lot of scrutiny by almost everyone.

To complicate matters his sister (who’s a magical swordsman) is against him going into summoner school to train there as a summoner. Because summoners and magical swordsman have a cat mouse thing going on where summoners look down on magical swordsman as inferior so his sister naturally is against him going there. She’ll stop him even if it means going to war.

Kazuki however is determined to thrive in summoner school and has already determined to give it his all. Even if he’s the lowest ranked student (ranked E) and his fellow students intend to demean him he’ll prove himself as the strongest summoner.

Feng Lingxi was the traditional family’s head mistress – a person with a charismatic yet sly personality with the ability to attract people easily to her side, and having the potential to take someone’s soul away. Crossing across boundaries from a decade ago to now, a world that gives woman full respect and acknowledgement….

Don’t be fooled by her, because she was someone who would act obediently in front of a crowd but, stabs them in the back when necessary! Disguising as someone that would gain her trust and belief! That was why the Emperor of Xian started doting on her, allowing her to become absurdly daring to do whatever she liked. This made the Empress speechless to tears.
That would be the cause of the kingdom’s downfall in the near future…

- Description from Novelupdates

In the back of the forest lives Allen, the antisocial wizard. He is feared by the people around him and called the “Demon Lord”.One day, while living out his life as a hermit, he finds a young girl named Charlotte who collapsed. Although innocent, she was accused of evil wrongdoings, had her engagement broken and was forced to flee her country.Upon hearing that, Allen recalled the bitter experience of being betrayed by a party he once believed to be his companions. Hearing the story of the 17 year old’s exploitation, Allen decides, “I’ll let her live in my mansion, and I’ll teach her all sorts of bad things…”