MTL - Naruto: The Village is on the Verge of Bankruptcy, I Dug Out the Oil - Chapter 8

The eldest daughter of the Yan family, Yan Jinyu, who has been missing for 16 years, has been found. She is brought back from an orphanage by her fiancé, the Second Master of the Yin family.

This is a world where humans, demons and mysterious beasts coexist.

Humans cultivate mysterious qi. Demons cultivate corporeal bodies. Mysterious beasts cultivate soul perception.

A legend says that in the middle of an endless rainforest, there are extremely powerful existences; they are called demon kings.

Some demon kings have a tyrannical corporeal body, some are experts in illusions.
Some demon kings are proficient in magic, some can even move mountains.
Some demon kings are able to sense things thousands of miles away.

These demon kings rarely appear in the human world. Even if they emerge in the human world, they would reincarnate in human form; assimilating with mankind while seeking to breakthrough realms…

- Description from Novelupdates

Xue Xi is forced to fall in love at first sight with this dangerous man on their first meeting. With death being the only other option, she makes the first move:

Usami is a beautiful classmate with good morals and top grades. At school, she views Sakuto as her rival. But when he bumps into her after school, he sees a different side of her. She was playing at an arcade after classes, and she had this innocent smile that one couldn’t imagine on her at school.For the sake of getting along with her, he gets close to her at school and then plays together with her after school. They each have their places where they can deepen their bonds, and at last…This is the start of a heart-warming love triangle romcom!