There Is A Huge Problem With My Achievement System - Chapter 1 - Carrying Rice up the Floor

Mu Mu transmigrated in the novel that had the plot like a fraud marriage with a man dressed in women’s clothing, rich man regretting and taking revenge after rebirth.

The body he had transmigrated into was none other than that of a scumbag who was a fraud man dressed in women’s clothing. He was also the one that the protagonist took revenge against.

And now, he was standing at the door of the Civil Affairs Bureau with that damn protagonist, holding the newly-released marriage certificate in his hand.

Mu Mu agitatedly raised his head. He saw the fierce and sinister expression on that damn protagonist. He was twitching the corners of his mouth, showing a grim smirk of wishing to eat his blood and flesh.

Mu Mu’s legs were weak and his eyes turned dark. He was trembling: “My good brother, why don’t we get a divorce?”

- Description from Novelupdates

The eldest son of the assassin aristocrat Tuatha Dé.

The skill, experience, knowledge of the previous life, magic, all of which grows his power as an assassin.

Excellent assassins pass through. He was usually admired as the ideal lord, and behind it wielded a blade as an assassin aristocrat.

After the soldiers’ mercenary group where he used to work had been utterly destroyed, Loren, who survived the disaster, decided to walk the adventurer’s path as a way to make a living. However, for Loren who had no acquaintances and nothing but an empty pocket on him, receiving a single quest seemed like a faraway aim. So, as he was contemplating about what he should do next, another adventurer called out to him.

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.