This battle fantasy manga follows several heroines who protect people from the monsters that appear through a gate connecting to an alternate world known as the Mato (magic capital).

Aijou experienced 100 heartbreaks during Junior High. While praying in a shrine, the God of Love appears, saying that Aijou will meet 100 fated girls. If their relationship with him fails, all the girls will face an accident and die. Now it's a matter of love or death, and it's up to Aijou to decide.

Ao Sato is accidentally swapped with himself in a parallel world with a male/female ratio of 1:39.

He finds a kind family and lovely women at the place where he was switched.

Seeing the outside of these women, he's relieved to see that the number of men and women has changed, but not much else.

However, their inner lives are filled with conflicts and troubles.

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.

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.

By some ill fortune, Hikaru died in a traffic accident. He was in heaven standing in line, waiting to be judged, when he took an unexpected request to transfer his soul to a person in another world. He received an ability called Soul Board which he could use to allocate points to Skills to make himself more powerful.

But there was a catch…

「I want you to kill someone for me within an hour. If you don’t, I’ll destroy your soul.」

To pull off the task assigned to him, he poured all his available points to the Stealth skill tree.

This is a story of a boy who specialized in Stealth. With his skill trees as weapons, he would demonstrate his unrivaled strength in another world.

Though Ayase Yuu is the son of a renowned and talented actress, he is below average in anything he does. He is entrusted to live under the care of his mother's friend, and later discovers that he will also be rooming with the three sisters from his school who possess both beauty and talent. Though Yuu thought that an understanding would be impossible to reach between an ordinary person and those blessed with talent, the three sisters are surprisingly...?!

The spaceship which Imperial Galactic Navy Officer Alan Corinth helmed was shot down by a surprise attack during hyper-space navigation.
Completely due to freak coincidence, Alan became the only one in the ship to survive.
The severely damaged spaceship lost its navigation capabilities and plummeted onto a nearby planet.

Using an escape pod, Alan headed toward the planet alone.
Thus began Alan’s quest for survival on the underdeveloped planet utilizing the symbiotic nanomachines [Nanom] within his body.
Surprisingly, the planet was home to a thriving human civilization whose genetic code closely resembled Alan’s own.
Even while remaining at a loss due to being thrown into a world of swords and magic, he tries to live as best he could together with his newfound comrades.

What would Alan achieve this strange world?

The Sci-fi Fantasy story in a Medieval setting now begins!

There has been much conflict between the races of the 'Humas', the 'Gabranth', and the 'Evila'. To combat the 'Evila' race's Demon King, the kingdom summons five high school students from 21st century Japan who have the power of Heroes.

However, only four out of five of those students had the status title of 'Hero'.

Okamura Hiiro was summoned by accident since he sat near the other four students in class. Unlike them, he did not have the title of a 'Hero' but instead he had the title of 'Word Master' and 'Innocent Bystander'. Seeing through the 'Humas' kingdom's deceit and insanity, Hiiro decides that he has no wish to partake in their selfish war. Leaving the castle, Hiiro decides to join the Adventurer's Guild and does whatever he feels like. Who knows? Maybe there is some merit to being a 'Word Master' and an 'Innocent Bystander'.

A man who was once called the world strongest agent ended up becoming a teacher after his retirement to train the new generation of agents. After many years of training his disciples, he is killed at the age of 60 by the ploy of a secret organization and was reincarnated in another world with all his past memories.

Though he was surprised by the magic and the strange species of that world, he adapted very fast to his condition as a newborn and took advantage of it. He acquired special magic and gained a massive amount of strength thanks to his tight discipline, in order to reach his goal: Resume his career as a teacher which he left halfway through in his previous life.

This is the story of a man, who, based on the memories and the experiences of his previous life, became a teacher who travels through the world with his students.

Kokonoe Yukito has always been unlucky when it comes to women. He was rejected by his childhood friend, which he thought they had mutual feelings for each other. He sister hates him. His mother neglected him— Due to all these trauma stacking with each other, his emotions were completely destroyed. When Yukito enters high school, the girls who inflicted these pain on him started to care for him...?! Thus commence a youthful Romcom full of misunderstandings!

Takayuki Shinohara (32), a librarian, gets caught in an earthquake, and wakes up in another world!?

Apparently, he’s now the son of a high-ranking noble, and he wakes up right at the scene of his own engagement being called off…!?

With his mind-reading skill, he aims to leave his mark!

A reincarnated-noble fantasy full of intrigue and adventure!

“Please teach us naughty things.” One day, Itsuki is transported to another world, where he is confronted by sisters who serve the goddess. In order to return to the real world, he must give them practical sex education!

There is only one Magi Craft Meister in the world. After the death of the last Meister over one thousand years ago, Jin Nidou was transported to another world in order to succeed her will.After obtaining the knowledge of the Magi Craft Meister, Jin attempts to use a warp gate but it malfunctions, transporting him to an unknown place. Along with that, an automata he recently restored also uses the warp gate in order to search for her “father”. Thus, the crafting journey of the new Magi Craft Meister begins!

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?

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)

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.

I, Sora Satou, woke up to find myself transported to what they call a "reverse chastity world." Although I was confused at first, little by little I adapted to this new world’s values and eventually ended up working at a supermarket across from an all-girls high school. Just when I had finally gotten used to life as an employee under the kind and beautiful manager, a rumor started spreading: "That male employee... they say if you ask him, he’ll let you do it." And so, a group of beautiful girls who took that rumor literally began to gather around me...

What am I supposed to do now!?

A male to female ratio of 1:359?! Saotome-kun is admitted into a school full of gyarus.

The strongest doesn’t need any cheats!

Haruka, who spends his high school life a loner, was suddenly summoned to another world one day along with all his classmates.

When ol’ God enters the picture, Haruka believes he can just choose whatever cheat skill he wants to help him survive in the new world...
But, contrary to his expectations, that list of cheat skills works on a first come, first serve basis. And so, his classmates pick out all the cheat skills.

His choices now limited to leftovers, Haruka finds himself incapable of assembling a party due to his own “loner” skill.
Even though it’s a different world, it seems his adventuring days will be, as per usual, a solitary affair…

After becoming aware of a crisis looming over his classmates, Haruka makes a silent vow to save them. No relying on cheats!
He will walk a heretical path of strength that transcends the need for them.

The curtain rises on the strongest loner’s otherworld strategy guide!