I Became the Demon Lord and my Territory is an Uninhabited Island - Chapter 15

A data loving young man from Earth has an accident which transports him to a dark land filled with terrifying creatures and magical powers. Fortunately for him, he has a Biological Assistance Chip to ease his path. However, things in this bizarre and strange world are not always as they seem, and, though it is a tremendous asset, the chip doesn’t always work as expected. With all of the crazy creatures and magical mayhem around him, one can only wonder what the future holds for this young man…

“I really feel like having one of those special macarons from the cafeteria today. You think you could get me one?”I sit diagonally behind the heroine in class. I’m basically her errand girl.“We are [friends] , after all.”…And I’m happy to do it.

Silas Blackwood wakes up with a machine in his chest – his missing mother's parting gift to help him survive the war with the Fae. This “system” grants him bizarre abilities: neuromancy (magic of the mind), biomancy (magic of the body), and essomancy (magic of souls and essences). Oh, and it fused a leviathan's mana core into his body. Because why not become part sea monster?At Arcanium University, a military boot camp churning out mage knights, Silas finds himself targeted by rich brats who think being born with a silver wand up their ass makes them special. When they leave him for dead, Silas decides it's time to show these spoiled kids what real power looks like.As Silas grows stronger, he discovers he can upgrade himself by absorbing essences from magical beasts and demons. Just when he thinks he's got a handle on things, Silas learns his mother's alive, and now he's got a new mission: a rescue that'll take him and his friends straight into the depths of Hell.

She shouldn’t have got drunk, so she wouldn’t have court the troubles.
She slept with a handsome man and would be sent to the police?
Oh, my sweet Jesus…
“So you just ran away like nothing happened after you slept with me?”
“Old jerk! Even if I had the initiative, it was you who took advantage of me!”
As a saying goes, the more spoiled a president gets, the more likely he becomes a scumbag.
An adorable ‘wildcat’ vs. a scheming frenemy.
This was a love rivalry between a modern Cinderella and a Big Boss.
As time flew, the world was like a fleeting show.
When they met again after several years of separation, he held her hand tightly and swore that he would never give her any chance to leave him again!
Finally, he asked her to marry him and pampered his cute wifey with his endless love.

- Description from Novelupdates