As the Minor Gay Love Rival in Het Novels - Chapter 6.8

Perhaps it is the choice of fate. As a senior otaku, Qian Lingfeng got the “steel shell system”. However, when he swept the world with the system, became a local rich man, made all kinds of beautiful women, opened a harem, and realized the ultimate fantasy of thousands of otaku, he found that things seemed far from simple!
When the end comes, biochemical zombies suddenly come down, fierce beasts are in power, bloodthirsty zerg roam to kill the world, and human lives are comparable to dirt. Where will weak human beings go in this world? Is humanity going to be extinct? Or … can an otaku save the fate of the human race?

- Description from Novelupdates

She was stupidly in love with him. Because of him, she became rude and unreasonable, overbearing, jealous, insane. But he did not spare a glance to her. Married for two years, he didn’t favor her once, letting her become the laughing stock of the whole world. Eventually, she ended up in an affair, leading to her tragic death.

“How can such an unscientific thing be possible?”“If it's true, wouldn't we be able to rule the world?”“You think so, don't you, Mr. Gin?”“By the way, could you please sign an autograph for me?”“Use your real name.”————Since the disappearance of high school detective Shinichi Kudo, the death rate in Beika City has been increasing.But it doesn't matter, Hayashi Yoshiki will take action.He will make the whole world keep up with Beika City's pace.

This book is also called “The Unscientific Ninja Master of Sand Ninja Village”.

“Gara, come on!” “When oil is dug, Sand Ninja Village will explode.” Gaara was puzzled. He was outraged. ”

Teacher Mu Feng, shouldn’t hard work mean hard work in cultivation? You always ask me to dig sand and find oil for cultivation. ”

“Scientifically speaking, digging sand is a very good exercise.”

“Just dig hard. If oil is dug, everyone in Sand Ninja Village will have a white cloth on their head. I will be the richest in the world.”

- Description from novelbuddy