Long ago, a powerful demon lord ruled over the people until an equally powerful hero rose up to defeat him. To counter future threats, Rosewood Academy, a school for heroes-in-training, was created. Today, Rosewood Academy enrolls only the best of the best, and Arnest Flaming is the best of them all. The top student in the school, a dutiful girl nicknamed "Empress of Flame", she has an irritating encounter with a light-hearted boy in the school hallway one day who seems to equal her powers, though she's never seen him before. He introduces himself only as Blade, and Arnest soon finds out not only is he transferring into the school as a new student, but she is personally requested by the King to help him settle into daily life in Rosewood Academy.

Takeru Kamishiro is an ordinary middle aged salaryman who was chosen by god to be reincarnated into a fantasy world in the body of a handsome young man in his prime with a very large penis.

"Understanding" is "Stronger" than a Sword! There is no magic without any weapons!
But! This is the story of a man who wishes to live safely!
"So, I've come to a different world."
That man stood alone in a mountain full of plants and creatures that he never knew nor saw before. He goes down the mountain by avoiding encounters with a big slime (and bandits), and is caught as a suspicious person in the castle he reaches. In interrogation the female knight Ilius met at the imprisoned place, when talking about the bandits seen in the mountain, Irias, who was stuck in the search for said bandits, hurriedly strikes the bandits . My wish to be a brave man, or to build a harem?
"I just want to live in a safe place" - a story that such a man survives the different world with "Understanding" as a weapon!

Killed on the battlefield without glory to his name, Yuseong Dan receives an opportunity to grow stronger with a strange quest and level system. But each quest he’s forced to fight only seems to be getting harder and harder. Can he level up enough to avoid the same miserable ending and become the powerful hero he wishes to be?

Cassia Ruberno, Countess of the Simone Empire, marries Zester Greze, a commoner war hero, at the order of emperor. After living for 10 years with no love or money, he dies of incurable disease. No, I only thought that he was dead. At the same time as his death, Cassia returns to the first day she met him, 10 years ago. However, I don't want to repeat the same life as before, so I declared a "strike." Cassia, who was blunt and knew nothing but war, was determined to live on her own without being discouraged. Strangely, Zester in this life continues to try to get into Cassia's heart. Cassia, who didn't hate Zester’s efforts and changes at the same time, said, “I think that maybe I can manage change it in this life.”

To live from bottom-class to top-class farmer, our protagonist Aru Wayn levelled up his agricultural skills, and sometimes his other skills leveled up as well by helping out his friends. One day, when his last skill level hit MAX, his life changes.

"I want to live as a normal farmer!!"

An era where hunters thrive on hunting monsters that come from Gates. Jin Tae-Kyung is a low-rank hunter who picks up a VR machine, and accidentally logs into the game, which is set in the world of Martial Arts. After many ups and downs, Tae-Kyung is able to escape this world. The strength and skills, which he received in the Murim were able to be carried over back to the real world. This allows him to continue making a living a hunter... but he decides to return back to the world of Murim, out of care for his NPC friends.

This is comic about a high-school student's convenience store and OL (+ α). There is age difference & height difference.

As regular high school students Taichi and Rin disappeared in a beam of light. When they came to, the two of them were already in a world of swords and magic. Finally getting away after experiencing an attack by monsters, following the suggestion of adventurers they headed on the path towards the guild. In the guild, the two of them found out that they possessed unbelievably powerful magic. Thus the regular high school students transformed into the strongest cheats...

(Source: sylver135)

Marie, a domineering and selfish princess, faced her end under the guillotine's blade after her subjects had enough of her. But instead of staying dead, Marie finds herself back a year in the past, though no matter what she does she can never escape the fate that awaits her in a year.

Eventually, after Marie learns that the only way to escape her own execution is to conquer a large swathe of 'romantically troubled' women, she decides to use her own 'royal charisma' to build a yuri harem!

A survival yuri fantasy about a princess who defies death is about to begin!

Magnus, a mage who always got yelled at “just shut up and follow my orders!” by the Hero because he was deemed “useless”. One day after getting fed up with his party he left, upon leaving he met a merchant that sold him a mysterious book.
And it turned out that the book which was written in the god's language was actually an ultimate encyclopedia book that had a lot of useful information on how to defeat the Demon Lord!
Thanks to that book, he was able to know about boss monsters' weaknesses and raise his level more efficiently, data about important people, and it even had info on complete gourmet spots in any city! Moreover, by using his wits and scheming mind, he's even able to outclass the hero party! With the ultimate encyclopedia in his hands, advance to the true route to defeat the Demon Lord!

Magnus wasn't chosen by destiny to be the hero. That's why, He's going to beat the Demon Lord with his own power and wits and save the world.

An unknown skill turns into unlimited power with divine knowledge [Internet]!

"To manifest an SSS rank with the weakest skill is a disgrace!"

Rona is a girl who was expelled from her home due to her lack of money, food, and power. Lost and hopeless, she suddenly hears the words...

"Would you like some guidance?"

She discovers how to utilize her unique SSS rank skill: [Internet], which she alone possesses. The true nature of this skill is the ability to access this world's 'guide sites' - an extraordinary cheat skill! Endless production of valuable items! Acquiring ultra-rare equipment! Thanks to her skill, she can do as she pleases...!

There exists an evil organisation that intends to invade planet Earth.
The man called "General" fights everyday against the Earth's Defence Force, the "Rangers"!

However, today is his day off.

If I can succeed it's OK to use bugs or any possible way! A story of reincarnated ultra-high obesity young lord.

Ichabod is a young boy trying to find his biological father. This pursuit isn't made any easier by his tendency to get into trouble with the law. To top things off, his parents are just downright weird: Ichabod was raised by a lesbian couple. Thank god he meets Kirico, who is anything but ordinary.

Around the age of thirty, the officer worker Shouko suddenly gets into an accident on her way home and reincarnates into a parallel universe. When she reincarnates, a goddess gives her the "power of healing" and caretakers that will look after her until she is able to become independent.

However, she restarts in the form of a 10-year-old...

Prior to her reincarnation, Sachiko who opened her eyes on the verge of death was picked up by a handsome hunter named Falco. Shouko instinctively knew that Falco is one of the promised caretakers... but there's trouble.

Falco's constant doting can't be stopped!

Hunting slimes, harvesting herbs, and training to be a healer: Shouko then decides to live her second life with the overprotective and soft Falco.

Misaki-kun may be adorable, but he's just the 'best friend' type character you can find in any gal game. However, the protagonist, Kihara Hareta, isn't set on wooing any of the heroines; he has his eyes set on the Unobtainable Misaki-kun! Gender makes little difference in the face of such cuteness in this heart-stoppingly sweet comedy!

From MangaHelpers:

This 4-koma comedy manga follows the daily life of the intelligent, responsible 6th grade elementary school student Haruna Raika. She keeps busy as the elementary student council president and the classroom leader, and she even fills in for the teacher sometimes! [tethysdust]

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4-Koma comedy following the super genius grade school student Haruna Raika and her every day life. Where she's the class president, the room leader, the top student, and even fills in for the teacher when they've overslept!

Kazuma Satō, a hikikomori (shut-in) die-hard fan of games, anime, and manga. A traffic accident brings his disappointingly brief life to an end … or it should have, but he wakes up and sees a beautiful girl who introduces herself as a goddess. "Hey, I have some good news — would you like to go to an alternate world? You may only bring one thing you like with you."

He responds, "…So, I'll bring you." With that, he is transported to another world and his great adventure subjugating the demon king begins … but first the hard work of finding food, clothing, and shelter begins. Kazuma wants to live in peace, but the goddess raises one problem after another, and then the demon king's army has its eyes set on him.

Without possessing the unique skill blessed by the goddess, a boy named Kujou Kyouya failed to save the world. He was ridiculed as a “failed hero” at the interdimensional-level academy where returned heroes who had saved many worlds gathered. However, he became the strongest and most unique hero, having trained for 30,000 years in another world with the most evil demon king, Felice, who has destroyed 3,000 worlds! Now Kyouya’s unique skill is so powerful that he cannot even be defeated by the strongest heroes! The legend of a boy trained by the most evil demon king, begins!