Kami no gyakuten:The yamato hero - Chapter 45: The Birth of the Dark Guardian

Zhuang Feng is in his last year of high school, and he’s just moved to the city. He lives with his good-for-nothing cousin, who’s always on business trips falling for get-rich-quick scams, and his Saozi (sister-in-law), who tries to make his life miserable as much as possible. There’s one upside, though; she. is. freaking. hot. But one day, he found a piece of her underwear in the bathroom…. And unfolded a series of events that will turn his life upside down.

- Description from Novelupdates

Another entry in what you can call the Proto Harem Series: the books written before the Harem Series that take place in the same world.

It’s about a swordswoman whose student is captured, so she goes to rescue her.

This is the story of a poor young man whose poverty even shreds apart their family willing to climb his way through society and into the top

Akun, along with his classmates, was summoned as heroes by a goddess to save the world from the demon king. Akun, doubting he has what it takes to save the world, asks the goddess to send him back. Little did he know that this request infuriated the goddess. “How dare a mere mortal go against my will,” she thought to herself while maintaining her facade. She opens a portal for him to go back. Little did he know, the goddess had something else in store for him. As he passed through the portal, his soul was separated from his body, and he fell through the sky and earth until he landed in the body of an ant in the godforsaken forest. Left there to die by the hands of the goddess, Akun awakens the “Endless Evolution System.” [Ding!! The Endless Evolution System has been activated!! Grind to gain evolution points and evolve yourself and your comrades!!] “Endless Evolution System? Evolution points?” “Does this mean there’s more to my transformation? Can I evolve even as an ant?” [Ding!! Unique skill detected!! Skill: Super Gamer Shop!! Evolution points can also be used on this skill to buy items!!] Follow Akun on his new epic adventure, and find out exactly what awaits him, maybe some conquest and retribution.