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.

I’m Shinomiya Hokage, a 3rd-year high-school boy who dreams of a survival life. One day, everyone in my school transferred to a mysterious island in a parallel world. I woke up in an unknown cave and I started moving on my own. Then, I met up with some of my classmates. My knowledge and tools in survival shines through. I was a plain guy in school but I’m the leader in this 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.

Nakayama Haruto is a game commentator who streams provocative content under the name "Oni-chan." He attracts attention for his radical streams , but his true identity is that of a good older brother who streams to raise money for his younger sister's tuition and living expenses. However, he accidentally forgets to turn off the streams, and his true personality is revealed to the public. Just when it seems like he's going to cause a major uproar, the contrast with his usual self turns out to be a big hit with viewers...!?

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!

From their worst encounter comes a story about their ultimate happiness! This romantic comedy explores the ups and downs of a serious relationship.

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!

Due to an accident, the protagonist Varius died and was reincarnated. He was shocked to find in this new world, his former job as a Tamer in the previous world was acknowledged as a low class job in this new world.

Utilizing his knowledge from his previous life as a basis, he then applied unique buffs to his beasts, taking back the ultimate power that he once possessed.

With this power in his hands, he sought to start his life as an adventurer. However-

Artist's Twitter (NSFW): https://twitter.com/NiwaRhythm
Webnovel: https://ncode.syosetu.com/n7251fq/

One day 's lunch break, suddenly a male high school student Yuzo Ogata being transferred to another world of sword and magic together with four other friends.

According to the Princess of Space-Time Magician, a foreign world who summoned them, they want them to beat the Demon Lord as Heroes to save this world.
Suddenly I was surprised at four friends "Temple", but it was a relaxing expression ... ... where the princess told of a startling fact!
"`―― There should only be four braves though?"
"A man who was mistakenly summoned to a different world" What will be in store as to his fate?

Source: http://konomanga.jp/manga/taitei-cheat

Youki was reincarnated in another world. However, instead of being reincarnated as the hero or the demon lord, he was instead reincarnated half-assedly as a minion of the Demon Lord. One day, the Hero's Party attacked the Demon Lord's castle with the intent of defeating the Demon Lord. Of course, Youki was able to repel their attempt with ease. In spite of this, he ended up falling for the cleric, Cecilia, at first sight… The super popular love comedy fantasy set in another world! (Source: Gaugau)

Uesugi-kun is a boy who's as petite and cute as a girl. He has a crush on a girl he's known since childhood, but overheard her saying, "Wouldn't Uesugi be totally adorable if he was a girl?!" Uesugi-kun's not as tall as his other childhood friend, Eito, nor is he as good at studies, and now he's suffering from a broken heart. A depressed Uesugi-kun stops by a shrine while running an errand and makes a wish... A love-triangle romantic comedy featuring an overly cute, and now female, protagonist begins!

In the summer of his second year of high school, the protagonist, Yuushin Tahara, finds that his childhood friend, Miyu Fukagawa, who had moved away, has returned to the house next door. Although Miyu has grown up to be quite cute, there's something a little strange about her... This is a fresh and suspenseful romantic comedy about the gentle protagonist and his cute but rather quirky childhood friend, along with their friends and the adventures they get into!

From MangaHelpers :
High school student Misumi Makoto is called into a fantasy world by the god Tsukuyomi, in order to be a hero. However, powerful others in this world aren't as thrilled to have him there, and they kick him to the edge of the world just as Tsukuyomi declares that he must leave Makoto to find his own way. Now it's up to Makoto to find his own way.

If you become a hero and defeat the Demon King, a life of idleness awaits you...! This is what the young man Jirei believed, and he worked hard day and night to achieve his goal. However, when he found out that the heroes who defeated the Demon King were the ones who were doing all the hard work, he ran away. But the girls that Jirei had been saving on his journeys before he knew it came pouring in one after another to win his heart and body...?