When the Devil King announces his retirement, he calls forth his two sons, Yomi and Sora, to give them each a quest. Whichever of them finds a pure Yamato maiden within a year would inherit the throne of the Devil King, while the other would die. Thus begins Sora's sex-fuelled adventure to find a woman that can satisfy his father...
(Sakigake!! Otokojuku Wiki)

Zhuo Yifan was a magic emperor or could be called a demon emperor because he had an ancient emperor’s book called the Book of the Nine Secrets, he was targeted by all the experts and he was even betrayed and killed by his students. Then his soul enters and comes back to life in a family servant boy named Zhuo Fan. Because some demonic magic is holding him back, he must unite the child’s memories and cannot ignore the family and the mistress he serves. How can he lead this descending family back to the pinnacle of this continent!

A long time ago, a portal to another world was opened, and those who acquired special abilities along with marks began to be called mages. After the incident known as "that day", the first-class mage from Ophion, known as "Blow", has become very famous. One day, he receives a very special mission: to protect the second son of the Artian family, who suffers from being called a "monster" at the magic school "Helios"! Thus, Blow enrolls in Helios under the name "Rood Krisch" to hide his true identity...

A fluffy story about a coworker who can't express her love for her subordinate.

Minjun Kim, an ordinary high school senior in Korea, was suddenly summoned to another world, where he became a dark mage.

Determined to return home, he overcame all sorts of hardships and saved the other world with black magic before leaving all his wealth and glory as a hero behind to return to Earth.

However, before he could fully enjoy his life, a problem arose. A dungeon break had occured and monsters came pouring out, threatening his comfortable days.

Therefore, Minjun, who had just returned to earth, had no choice but to… enlist on the very next day!!!

From MangaHelpers:
People have been created that are human-animal hybrids, and powerful businesses bet on the outcome of their duels. College student Nomoto Yuuya's casual acquaintances ask him to drive them around to pick up girls one day, which he soon finds out means by force. The girl they kidnap is an animal-human hybrid named Hitomi, who slaughters all of them except Yuuya. Hitomi is a honey badger, which has been called the most fearless of all animals. Now Hitomi is assigned to stay with Yuuya, for his protection.

“I was given a building as an inheritance?”

From a nobody who does all kinds of odd jobs and lived a hard life, he was given a chance to become a landlord right in the middle of Gangnam!

But, the condition for this inheritance is to ‘operate a restaurant for 5 years.’

‘Moreover, I can sense a chill down my spine thanks to the weird customers that came in for today’s store opening……Do I really just need to prepare food?’

“So then…all the guests who came in yesterday…”

“They were ghosts.”

Every night starting from 11 o’ clock until 1 o’clock, we will now be open!

Kim GiGyu awakened as a player at the age of 18. He thought his life was on the track to success, climbing 'the tower' and closing 'the gates'... But even after clearing the tutorial, he was level 1. He killed a goblin a day, and he was still level 1. Even after 5 years, he was still level 1. "Who would have thought that this kind of player would exist." No one knew.

Zeke Draker, the first direct descendant of the Dragon Slayer family to fail awakening. Possessing the talent of a healer instead of a swordsman, he was cast out by his family. Struggling desperately to grow stronger, Zeke met a tragic end.

At the moment of his death, mysterious words appeared before his eyes:

[The soul of an Elder Dragon is engraved upon the will of the one who persists.]

[An irreversible, promised power is being activated.]

When he regained consciousness, he found himself back in the Dragon Slayer family that had abandoned him, 20 years in the past.

"If I can become strong, I’ll make use of anything and everything."

Armed with a newfound, immortal power, the legend of a Dragon Slayer in a class of his own begins.

The worst talent that no one can compete with.
Unstoppable Demon God, Dan Uhyeon.
A thousand years after being sealed for the misdeed.
A thousand years was enough to get rid of Dan Uhyeon’s sense of superiority.
A world that has changed, solitude with no one knows, and the only thing left is despondency and emptiness.
“Time goes like the wind. There’s really nothing left.”
A little girl who appeared in front of Dan Uhyeon lost her purpose and will to live aimlessly. Hwa Somi.
For a girl who seems to have nowhere to lean on, Dan Uhyeon feels the same and gradually begins to open the door of his mind.
“I’m Dan Uhyeon. Come with me.”
The story of a warrior with an icy heart and acute and pure girl
The story of an unusual family’s life in the midfield will warm your heart.

Liz who remembers being dumped by her lover in her previous life decides to live freely in her current one.

Holding a mysterious power, she was invited to the palace as a saint candidate where she meets with the crown prince who was actually her former lover from her previous life.

Though Liz looks to be the weakest among the saint candidates she is (likely) the strongest among them.

After diligently following the “demon king’s standards,” I ended up getting killed by the heroes.

What, my tower and I are a custom-made hunting ground for heroes now?

With this chance at life regained through regression, to hell with the damn demon king’s standards!

This is the story of surviving as the hard-headed(?) demon king, Berje!

I, a corporate slave, transmigrated into a game as a noble. But I'm just an extra that will die at the hands of the villains in the future? No way. I'll somehow reform them and live a lavish life! For this I started sponsoring the future villains to prevent them from turning evil and helped them overcome their difficult circumstances. As a result, they all grew up to be upstanding and ordinary, enough to make me feel proud. And so, I became the ultimate mastermind of the kingdom... Huh?

Dirty oldman isekai

Fantasy harem-comedy begins with a kind-hearted uncle who helps the weak, crushes the strong while doing some consensual seeding here and there.

Kill monsters, save your neighbors, and expand your domain, all from the comfort of your couch. When his city becomes infested with monsters, Jaehyeon discovers an ability that makes him the absolute master of his apartment building. But his ability comes with a catch -- he cannot leave his apartment. Now, he must arm his neighbors and lead them beyond their building to survive the post-apocalyptic world they find themselves in.

Kim Suho, who’s a civil engineer, became a Noble inside a novel.

So what? My estate is about to fail? Then it must be saved. To design, build and sell.

The awaited special opportunity all over the continent! The perfect transportation, highest educational district, pleasant forest area, and a one stop premium estate life by Baron Frontera that everyone has been waiting for.

A first-come-first-serve basis contract!

The princess of the human kingdom has been kidnapped by the demon king!

But all she wants to do is get a good night's sleep!?

Gag driven, short episodes built around an insane third-year high-school girl (Nee-san), who likes building plastic models in a model-making club along with fellow club members Makimaki and Okappa.

Humanity, love your little sister.

I miss the time when her younger sister Kana was fond of me.
Takashi Shiina lamented the current days when he was often ignored.
One day, his parents cut out a shocking story.
Surprisingly, he wasn't his real son... but he was his sister Kana's fiancée! ?

The definitive version of Reiwa's younger sister manga!

Every time she opens her mouth, it's nothing but abusive language, and her problematic behavior never stops. The protagonist has had enough and sets a “plan” into motion…??!