Katahane no Riku - Chapter 20.The festival at Derufoi

A man betrayed by a comrade dies a wretched death as a third rate swordsman. His existence, his life, his emotions are all a nuisance in the eyes of society. But wait… What’s this green skin? Reincarnated as a goblin? Wait, I went back in time as well?

She went out of the way to help him build a business empire and get his inheritance. When she thought they would live happily ever after, she and her entire family were quietly gotten rid of and burned to ashes. As the blaze seared her skin, she was overcome by deep hatred and bitter regret, and wished she had another chance…

Dizziness jolted her out of unconsciousness.

She is now known as Miss Su. She tried to run from her wedding, but slipped and fell in the river, which incidentally, brought great shame upon both her and her fiance’s family. The word on the street is that her fiance is a playboy, a make-out king, and a bit of a lady’s man. But she has to salvage this marriage to carry out her revenge plan.

And… the more she gets to know her future husband, the more she needs to find out. He turns out to be much deeper and more sophisticated than he cares to show to the outside world.

- Description from Novelupdates

An Individual from Earth finds themselves in the Shinobi World, equipped with a Scientific System. From that moment, he delved into scientific research far ahead of its time.