MTL - The Demon King Always Thinks I’m Secretly In Love With Him - Chapter 39

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

The unparalleled Demon King Ye Xuan, who was able to heal the death or the living alike and holder of the medicine Holy Scripture, was betrayed and killed by his fellow Demon Kings. But he reincarnated into the body of Ye Xuan, the prodigal son of the Ye family and vowed to himself that he would return to his peak and take back everything that belonged to him!

- Description from Novelupdates

Yeho is a distant relative to a king in a small kingdom. Even though he is a distant relative, his house was very poor, and his mother was addicted to gambling. One day North Empire asked for Princess Sooyoung to be a concubine of an old Emperor because she was known for her beauty. But the king really loved his daughter so instead he ordered Yeho’s older sister to disguise as Princess Sooyoung and marry the old Emperor.

Yeho told his sister to run away with her lover, and his sister had to leave her younger brother alone with his mother. After she ran away, Yeho asked his mother to give the things back to the king that she got for trying to sell her daughter, but his mother already used the gifts to pay off her gambling debt. He was trying to give the gifts back to the king to take away his order, but now he can’t do that anymore. He tells his mother to run away, and he disguises as his sister to go to North Empire.

After he got there, he was trying to tell the Emperor the truth and take away his life, but the Emperor went out for few days to look around his empire. When the emperor came back, he wasn’t as old as he thought.