In Different World with Naruto System (WN) - Chapter 44 Combat skills

“Married rich for three years with no child born. Just when she was finally cured of infertility and ready to give him a child, he brought home his pregnant mistress in high profile.

Yang Qing never expected that he would travel to the fairy world, let alone that he would have a chance to travel back.

It’s just that after I came back, I found out that this world is not friendly to cultivation, and it’s a completely degenerated world, so what else can I do?

Part-time work is not allowed, so he can only rely on the rune technology of the fairy world and develop a little black technology to live his life, so his eyes are directly fixed on the moon above his head, where his dream begins!

- Description from novelbuddy

What does “being perfect” mean to you? To Hashidate Yuuto, it means everything. All his life long he strived for perfectness until a single incident occured in middle school that ruined his plans of being perfect: He pooped in front of the whole class and parents. Believing, that his reputation was destroyed and that he would never be able to reach perfectness anymore, he wished that the incident never occured. This is when a mysterious Goddess named Maki offers him a button that allows him to go back in time.

Based on the popular Vocaloid song “” by kemu.

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