MTL - Plane Source Code - ~ Death battle

On the surface, she’s a gay high school boy. In reality, she’s the hacker known as Z, who hunts criminals on the Internet. A girl dressed in men’s clothes; a master at playing games, punishing evil, and having the highest skill in seducing girls. When people learned that “he” was actually female, the entire population blew up!

Ji Qingqing was at the end of her rope. When she was on the brink of wretched poverty, she received a system. The system told her; Lu Lixing came from a family that was rolling in money, but he was coming to the end of his allotted lifespan. If she married him, she would gain his enormous inheritance.

Lu Lixing was seriously ill. Just as he was about to die, he gained a system. The system told him: Ji Qingqing was young and beautiful. She was rich in vitality. If he married her, he could continue living.

Ji Qingqing happily came to Lu Lixing’s sickbed.

And then, Lu Lixing woke up.

***

Lu Lixing’s friends discovered that after Lu Lixing woke up, not only did this person that had always kept his distance from women gotten married, he spent every day being super clingy towards his wife.

Young Lu, can you be a little less embarrassing and act your age? Will you die if you take one step away from your wife?

Lu Lixing clutched his chest. His little heart had almost stopped beating because Ji Qingqing had left him for half an hour. He weakly waved his hand. He couldn’t be separated from her, not for the rest of his life. She was his life.

- Description from Novelupdates

This stands at the forefront of strategy guides to Life (a shitty video game)!

King Grey has unrivaled strength, wealth, and prestige in a world governed by martial ability. However, solitude lingers closely behind those with great power. Beneath the glamorous exterior of a powerful king lurks the shell of man, devoid of purpose and will. 

Reincarnated into a new world filled with magic and monsters, the king has a second chance to relive his life. Correcting the mistakes of his past will not be his only challenge, however. Underneath the peace and prosperity of the new world is an undercurrent threatening to destroy everything he has worked for, questioning his role and reason for being born again.