City of Sin - Book 9, Chapter 68

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.

Xia Zhijun got the title ‘study god’ after scoring first place in the whole city. He’s the model of a good student in a teacher’s eyes: good grades, good manners, and quiet. When he wasn’t smiling, his entire body emits a cold abstinence aura. The girls only have the guts to look from afar and not get close.
Later, it was rumored throughout the entire school that even the study god would fight and hit on girls. Whoever dared to provoke his girl, he would teach you how to be a person at every minute. The night of the graduation ceremony someone saw him blocking Gu Siyi in the corner. He didn’t stop kissing even when she cried. He bit her lips and said in a raspy voice, “I’m going crazy…”
During college finals, Gu Siyi almost bursted out crying, “I’m such a failure. I won’t be able to find a good job in the future…And if I can’t find a good job, I can’t provide for myself…”
Xia Zhijun played with her pink earlobe and remarked, “I’ll take care of you.”
After they graduated, Xia Zhijun created a research company and Gu Siyi became the boss’s wife.
The commercial rocket, “Star of Siyi” was successfully launched. So everyone knew that the new technology superstar, Xia Zhijun has a wife who he spoils a lot.

- Description from Novelupdates

After becoming #1 in the world after playing a grand strategy game as the most difficult faction on immortal level difficulty, MC receives an invitation to compete in an even more challenging game which takes the MC into the world of the game itself, but as it's weakest lord who will die two days later that appears only as a cutscene in the tutorial as first of many deaths to rock the continent until only one survives to proclaim a new eternal empire.Can the MC use his game knowledge to successfully survive his impending doom, and rise from the ashes to reclaim the glory he'd won before?

Transmigrated into the world of High School DxD, Roy believed he had been handed a life of luxury and glory. Born into the prestigious Lucifuge family, with his Sister Grayfia as his strict yet devoted older sister, he thought he was destined for greatness. 99,997… 99,998… 99,999… 100,000!!But... reality proved harsher: Roy lacked demonic talent and, despite years of training, remained a Low-Class Devil. his peers effortlessly achieve High-Class status, he’s been trapped in a cycle of endless sword practice and ridicule. Yet, he refused to accept mediocrity. Ten thousand sword swings a day, relentless training.. Until one day..[Ding! The Strongest Demon King System has been activated. Access functions to learn more.]---- High School DxD - Main World!1 - High School of the Dead [●] - First2 - Demon Slayer [●] - Second3 - Akame Ga Kill [●] - Third4 - Bladedance of Elementalers [●] - Fourth5 - Campione [●] - Fifth