The protagonist along with his step-mother, and 2 step-sisters are summoned into another world where demi-humans are the rulers as saviors, but its not to fight against a demon lord, its to fight an Undead Apocalypse monsters called "Dead Mell" that have overrun the world and that can only be killed by using weapons made with holy silver.

For that, a familia is made (group of 4 people) with them being the swordmaster that uses the holy sword, the guardian that uses the power of earth to protect, the healer that use the power of water to heal and the black mage that uses the power of fire to destroy.
The role of the guardian, the mage and the healer is to support the swordmaster that can only kill the monsters.

But to use magic powers one must offer part of your being as a sacrifice to form a contract with spirits, and the higher the sacrifice, the higher the power. Now they must choose who are the 3 that need to sacrifice part of their bodies to gain power and who will wield the holy sword.

This is a continuation of the story of Higanjima, featuring an isolated island surrounded by fish demons and a population of warring vampires and humans. Ryousuke, his girlfriend Kazumi, and his friend Yamaoka are shipwrecked by the fish demons and wash up on the shore of this cursed island. They soon encounter the inhuman cruelty of the vampires first hand, before Ryousuke is able to meet up with the human resistance. Ryousuke wants nothing more than to escape the island, but mainland Japan may not be safe for long. If the humans don't defeat the vampires soon, then the vampires will succeed in their plans to spread the virus to the mainland!

Distributing thrilling videos in secret. A school game that puts life and death on the line.

Circa 1937. A Japanese soldier in Manchuria meddling in the opium trade.

On the way home, Jin and his friend Komachi are suddenly transported to another world full of strange creatures and Jin is killed by them, but somehow manages to come back to life, but as a tentacled creature !? This is the start of a dark tentacle fantasy!

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

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.

Arisa and Aina are beautiful classmates who are famous for their dislike of men. Hayato, who happened to be involved with the two, will receive "special treatment" from the girls who are supposed to hate men―?! "I want to be a slave to Hayato-sama...

"I want to fall in love and conceive his child."

The long-awaited comicalization of the unpredictable rich romantic comedy has started!

One day at school, Youta Tada sees someone strange entering school. Out of nowhere this being appears next to him and makes him fall from the third floor! But before he hits the ground, he wakes up in a strange world where beings like dragons exist! Youta then meets a young paladin named Lumi and discovers that he is the only man on the entire planet, and also that its inhabitants are extremely 'weak' to his presence or more specifically, his touch. Would this be a paradise?

Rin's village getting attacked by bandits doesn't keep her down in the dumps for long! Picking up a sword housing an extraordinary pervert… I mean hero, Siegfried, she sets off on a journey of many bouts with various degenerat… ahem, heroes!

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.

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.

”Is it okay to kill people?"

A treacherous revenge suspense by Shiryu Nakatake, a newcomer to Bessatsu Shonen Magazine.

"Shun, if someone is converted, let him go and do nothing. He should be given a chance to be reborn."

"Grandpa, I hope he doesn't reincarnate himself."

In order to defeat several non-human monsters, the boy also became something non-human.

Shin Uruma, a sixth-grade student, was named "Experimental body: A" by five of his classmates and was severely bullied and lived in hell. His only peace was with his brother, who loved him, and his parents, who protected him.... . until the five monsters killed his family.

When he finally loses everything and faces true hell, a dark "wish" is born inside Shun. He was reborn under the training of his grandfather, who served in a secret unit during WWII. Now, four years later, he appears in front of his fated enemy.

"I won't let ANYONE get in the way of my revenge."

This shitty world that's nothing but a trashy game, he and I will definitely escape it together.

So, all these annoying women trying to take advantage of him are just a nuisance. What's worse, it seems like he's beginning to have some feelings for them.

That's why, for his sake, I'll eat them up first.

But, just what is this power...?

I'll take back my life. A cruel and beautiful revenge story of a princess who became a prostitute. Princess Evita lived happily in a small country. However, she was attacked by a neighboring country, her land taken away, and her family was brutally killed. The surviving Evita was sold to a brothel and lived as a prostitute. In the middle off all this, a man from the royal family that she hates appears as a customer...

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.

Average high school student Mikagami​ Kouji is a hardcore gamer. One day he gets isekai'd and he only gets the skill "copy" which is apparently useless but we all know it's secretly OP or something. He's enslaved to be a gladiator by his summoner, the big booba, head priestess Zayd. He has to fight in the Colosseum and if he loses he gets raped.

An introverted high school student, Souichi Sakuraba, is being bullied severely by the “Yokai” classmates. The bullying escalates, and Souichi’s childhood friend, Azusa, who was the only one who trusted him, is defiled by them. In front of Souichi, who was in the depths of despair, the succubus, Asmode, appeared. Souichi makes a contract with a succubus who possesses a mysterious ability, and decides to make the bully’s loved ones suffer the same pain as himself by “cuckolding” them. The obscene revenge by “NTR” begins.

The protagonist fell asleep while playing an online game. However, he awoke in a strange world with his game character’s appearance. In a state of shock, he noticed that he was equipped with nothing but his strongest weapon and armor. To make matters worse, our hero’s appearance was changed by the special avatar skin 『Skeleton』 when he enter this new world. The protagonist wanted to live without drawing attention, but he got acquainted with the dark elf Ariana and received her request.

Hayato is a young deity with a foul mouth who has always heard legends about Demons that were sealed away about 800 years ago. Follow the epic saga of several young deities, who end up having to fight demons, humans and overcome several challanges.

A remake of a web manga of the same name with new art by Cool-Kyou Shinja.