"A World Where Chastity is Reversed"—A dream world where the male-to-female ratio is 1:20, women have stronger sexual desires, and precious men live a smooth life protected by their bodyguards.

Fifteen years have passed since Ikuto Ichise was reincarnated into this world, which should have been a guaranteed harem, but for some reason, he isn't popular. Ikuto laments that it must be because his bodyguards are all handsome men, and especially his childhood friend Rui Toosaka, who is particularly high-spec... but in reality, the bodyguards are beautiful girls disguised as men! Completely unaware, Ikuto is overly close and unguarded, making every girl feel like they have a chance. As he unintentionally forms an oblivious harem, Rui, who wishes to be seen as a girl, reveals everything to him—!?

One night, Eizo, a hapless corporate slave, saves a cat and gets hit by a truck. The cat which seems to be related to a parallel world, in return for his help, grants Eizo a skill of his wish and reincarnates him to another world. Eizo, who has craftsmanship as a hobby and wishes to use this skill for a living, chooses to be reincarnated as a blacksmith. And so he starts his life in another world as a blacksmith just as he wishes. However, Eizo's creations are at another different level that will shake this new world.

Author’s Twitter: https://twitter.com/tamamaru
Artist's Twitter: https://twitter.com/himori_yoshino
Kadokawa Books (LN): https://kadokawabooks.jp/product/kajiyadehajimeruisekai/
Web Novel: https://ncode.syosetu.com/n7266fe/

Prince Rudolf gained knowledge of the future 300 years from now during a near-death experience. He uses his wits to change the future in which he will be assassinated as a tyrant prince.
Meanwhile, discrepancies between the story passed down to posterity and reality gradually emerge...

The middle boss of the AAA-class game produced by the company. The villain who dies 999 times out of 1,000 times. Deculein.
That person, was me now.
“You’re going to die on almost every route.”
Deculein, like all villains, inevitably dies.
[First and foremost survival goal: Be what the game requires you to be]
I’ll have to survive even if it means twisting my fate if I am destined to die.

A man was reincarnated as Van, a boy of noble birth, who grew up to become a child prodigy through hard work. But when it was discovered that he possessed "production magic," he was immediately relegated to a remote village. However, his magic, which was called useless, turned out to be truly extraordinary, capable of producing anything as long as he had the right ingredients! With the knowledge from his previous life and the overpowered magic, the small, poor village will grow to become into a great city.

Fia, who is aiming to be a knight in a family of knights, remembers her previous life as a "Grand Saint" when she was on the verge of dying. The saint is currently a highly important and respected profession because and is on the verge of extinction! The holy power she can use happens to be the "lost magic" of myths.

In her previous life, she was threatened by the right arm of the Demon King, saying, "I'll kill you again if you're reborn as a saint."

"If I use such power, I wonder if I would be caught and killed once again…"

Watch as she tries to live a simple life as a knight, hiding the fact that she's a Grand Saint!

The Mushoku Tensei 4Koma.

After the events of Baki-Dou, the famous Kenpo master Retsu Kaioh wakes up in a new world unknown to him.

Note: This is the official entry, not to be confused with the Doujinshi from Twitter user @sakuramankiti. As of now there is no official cover so the December 2020 issue of Monthly Shonen Champion is being used instead.

Realistic take on a modern doctor in another world treating fantasy creatures without magic or modern equipment

Mark Stuart had realized something terrifying: he had been reincarnated as the mid-boss in a game! In the original game, he was fated to be condemned by his daughter, Forsina, who was known as the “Ice Princess.”
Reflecting on his past coldness toward her, he resolves to change his fate by earning her affection. Through his thoughtfulness and his actions as a duke, his daughter begins to regain her love and trust in her father, but he ends up going too far, and her love slowly becomes overwhelmingly heavy!?

“Scramble Love” is a smash-hit Japanese romantic comedy manga with over 10 million copies sold.
I was thrown into the world of that manga—one I had never even read.
And not as a main character, but as a forgettable extra with barely any role.

Amamiya Hiroto is unlucky. His life consisted of misfortune after misfortune, culminating in an unlucky death during an incident on a school boat trip, trying to save a girl he barely knew. After death, he met a god of reincarnation who requested that the hundred or so dead passengers - one of them being the girl he tried in vain to save - be reincarnated into another world.

Yet a series of unfortunate events forced Hiroto to reincarnate with even less luck than before, starting with nothing but a tremendous amount of Mana. His second life, far worse than his first, came to a cruel end.

However, upon meeting the god a second time, he was informed that there would be yet another reincarnation - one that had already been set in motion and could not be stopped. Not wanting Hiroto to endure a third life filled with suffering, the god cursed him before he was reborn in the hopes that he would either die quickly or commit suicide.

Hiroto was reborn once more as a half-vampire, half-dark elf. A dhampir. Not wanting a fourth life, he is determined to live this third life with the only things remaining from his previous lives - Death Magic and his enormous Mana pool.

Receiving a secret mission from Callion of the Beast Kingdom Eurazania, an energetic animal-eared girl sets off to Jura Tempest Federation!

Arikawa Ougi, 16 years old, suddenly found himself reincarnated as a zombie?! Embarking on a journey to subjugate the Demon Lord as a zombie hero, but the use of "power" requires a "price"...? A dark fantasy in another world.

After being reincarnated into another world where the chastity and moral values of men and women are reversed and women rule the land, Faust was raised by his mother as a rare male knight. He's quick to become a war hero with many achievements under his belt, but because he inherited his way of thinking from his previous world, there's a certain severe pain in his groin day in and day out when faced with the likes of a scantily clad Queen who may as well be in the nude or the sexual harassment of the well endowed Duchess he calls a friend, among others...

"If you were to disappear... I might just lose myself."

Arcs is reborn into the world of the wildly popular otome game Celestia Kingdom. He thought he was just a background character—until it's revealed he's actually the childhood friend of the final boss! Determined to avoid the bad ending, he throws himself into his daily life as her servant. But it seems the true cause of her descent into darkness is... her childhood friend!?

An unpredictable tale of master and servant, between a slightly (maybe more than slightly?) yandere heroine and an obliviously overpowered protagonist, begins...!

Eugene, a hero, is forcibly reincarnated by the demon king Venomzard. In a world far in the future, he becomes a noble boy named Julius. Freed from his "hero" mission, Julius decides to enjoy his second life and his school life. However, his brother, Gaias, mocks him, and his parents and teachers consider him a failure. Having been reincarnated with the immense power of his previous life, Julius unknowingly becomes a warrior ...!

Orignal webnovel: https://ncode.syosetu.com/n8910gh/

Cute but dumb as hell... and somehow still the strongest! ...Reincarnated as an ostrich beastkin with innate physical ability!?

With intelligence from my previous life, I lead a flock through a monster-filled hellscape just to stay alive... One day, after saving a party of human adventurers from certain doom, I finally made contact with the civilized world I had dreamed of!!! Unlike the uncommunicative ostrich-kin I'm used to, I'm overjoyed to meet people I can actually talk to... However...!

Healing magicians cannot fight alone.’ Keare, who was bound by this common knowledge, was exploited again and again by others.
But one day, he noticed what lay beyond healing magic, and was convinced that a healing magician was the strongest class. However, by the time he realized that potential, he was deprived of everything. Thus, he used healing magic on the world itself to go back four years, deciding to redo everything.
This is a heroic tale of one healing magician who became the strongest by using knowledge from his past life and healing magic.

A normal office worker, Toru Minasuki, was swallowed up by a dimensional fissure and reincarnated into a different world. Upon reincarnation, Toru was given a [skill board] by God. Make the most of it to acquire all the necessary skills! Even though he is an "inferior person," he'll make his way to the top!
Webnovel: https://ncode.syosetu.com/n8516fu/