A mysterious syndrome turns schoolgirls into homicidal monsters behind numerous atrocities in Japan. However, nothing is what it seems and when Chika Amagi is arrested for the brutal murder of five people, which starts a journey into uncharted and troubled waters!

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.

From MangaHelpers:
People have been created that are human-animal hybrids, and powerful businesses bet on the outcome of their duels. College student Nomoto Yuuya's casual acquaintances ask him to drive them around to pick up girls one day, which he soon finds out means by force. The girl they kidnap is an animal-human hybrid named Hitomi, who slaughters all of them except Yuuya. Hitomi is a honey badger, which has been called the most fearless of all animals. Now Hitomi is assigned to stay with Yuuya, for his protection.

Tatsuo, Hide, Satoshi and Aya worked together to cheat people out of money. They tended to target marriage services, where they con money out of people looking for love. They were good at it, until they crossed the wrong guy. Then they saw the world below the surface of dupes to cheat, when the 'collection agency' came for them with extreme violence.

The person who takes Satoshi and Hide, and then Aya and Tatsuo, is a wild-eyed maniac who seems to get off on the torture. There may be hope for Tatsuo, though, because the man recognizes him. The torturer is "Akasada" a bullied kid that Tatsuo knew from school. Now Tatsuo and Aya have been pulled, against their will, into Aka's world. [tethysdust]

After killing the Demon Lord, Blum Dilmond was pursued by the kingdom and forced to leave the country. While spending days trying to avoid the assassins aiming at his neck, he suddenly came up with an idea. He could hide inside the dungeon that was once the Demon Lord’s hideout. If it’s there, then he could be safe.

Without hesitating Blum went into the dungeon, but then he met someone unexpected in the lower levels, one of his former companions with whom he fought side by side against the Demon Lord. Moreover, a maid, called Irene, who once served the Demon Lord is also there. And so since their interests happened to match, the three of them decided to cooperate together to rebuild the worn-out dungeon, working earnestly in order to turn it into their own safe paradise.
Links:
Author's Twitter
Japanese Light Novel ( on Amazon.co.jp )

A fantasy story about Kiska, a boy who is mistreated by the villagers. He manages to survive thanks to his childhood friend Namia, who was the only one by his side. One day, Namia is murdered by three men, and Kiska is accused of the crime and banished to an inescapable class S dungeon. However, he finds himself in a different world where he can use "Save and Reset" to get back on his feet no matter how many times he dies. The story is about Kiska's quest for revenge against those who wronged him and his friend

Ao Minato, a young man who killed his father-in-law who repeatedly abused his family and entered a juvenile reformatory. However, the sister who should have protected committed suicide at the end of suffering, and her sister Akane is also missing. Ao, who arrived at a certain shrine, wished for the safety of his sister, which is the only hope left, and swears to God that he will do anything for that ... The blockbuster panic suspense "Massacre Happy Ending". The new chapter is finally opening---.

10 years since he reincarnated in hell…Takamichi is troubled. With the “Incubus” power unlocking further to become stronger by having sex with women but his growth peaked. “I’ll move to a new area, wait for me beautiful women of the new world!” Sexy & violent pretty girl battle fantasy!

A girl who calls herself a devil appeared before a timid student named Fumio Kijima. The girl claims to be a campaign girl from the demon world and she gives him the ability to “summon a room” from nothing but thin air.

At first he doesn’t abuse his power and uses it as a convenient ability in his every day life. But one day he is bullied by his classmates under an unfair pretext and is made to suffer. In the past he would have wallowed in misery and cried himself to sleep, but now he had a power to call upon.

“I will make them regret it!”

Using his powers to summon his “room”, he begins his era of confinement and brainwashing to achieve his goals.

From MangaHelpers:
Nogawa Izumi is a good student, and a class representative, but she has an increasingly high libido. It's gotten to the point that she'll claim to feel bad during class, so she can run to the nurse's office and masturbate. When she learns that the Earth is being invaded by aliens that look like people dressed up as animals, it turns out her high sex drive may be able to help protect the Earth. The first time Izumi is attacked by the aliens, she is rescued by Usayama, a bunny alien whose race was their previous victim. Usayama gives her a swimsuit that will allow her to fight the aliens, but which also sends her constant arousal through the roof. The scientific organization that Usayama is affiliated with think that Izumi, with her high erotic level, may be the person they've been looking for to fight the aliens. Will Izumi be able to save the Earth?

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!

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 prequel series revealing Goblin Slayer's past and the events that led him to become an adventurer with the sole purpose of exterminating all goblins from the world.

Kanae is a girl who is struggling to fit in with the popular clique at her high school. Because she had been bullied in middle school, she has developed an acute inferiority complex that had led her to engage in compensated dating in order to feel wanted.

In comes Hiroshi, a high-school baseball star who became drawn to her after finding her crying during a group date at a karaoke bar. Thus begins an unhealthy relationship between a mentally unstable high-school girl and a jock.

Kazuya Kagami never goes anywhere without the precious Sakura Obi his mother gave him. One day a beautiful, kimono-clad girl named Kiriha appeared before him. Kiriha naturally began to live with Kazuya in his room. Then there's Chisato, Kazuya's childhood friend with glasses and a ponytail, who meddles in his affairs. Soon there's also an overprotective older sister who seems to want to take baths with him. Jumble in a huge-chested priestess, a good-looking sorceress named Kokuyoura, beautiful women, and hot girls, and Kazuya's happy, embarrassing, confusing life begins.

This apartment complex has a problem with perverted women!

Yoshida is a tiny, frail highschool graduate who became an unwilling manager of an apartment complex when his father, the former manager, injured himself. Unbeknownst to him, this apartment complex houses quite a few women with very... unusual sexual preferences. This becomes a problem when a mysterious entity begins giving "Libido Cloth" to these women - skimpy outfits that give them superpowers and cause them to go on lewd rampages! Will Yoshida be able to stop them?

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!

Raul who had defeated the demon king as the strongest hero should have become the savior of the world.

Having his treasured companions and family killed by power hungry aristocrats, he was executed with false charges brought against him by the princess. Just before his life collapsed, at last his heart fell into darkness.

...I will tear those traitors from limb to limb. Burn them at the stake. Sever them to pieces. Skewer them. I will kill every one of those bastards without mercy and make them taste hell's suffering.....!!!

Obtaining the power of darkness, Raul was revived. Sneering, he vowed revenge.

“Oh, I’m looking forward to it – from now I'll bask in their blood as I please.”

Several days after the hero's revival in the imperial capital where flowers bloomed in profusion, the parade that would advance towards tragedy began.

Fujinomiya Soujirou is transported to a fantasy world with only his Daisho (pair of samurai swords) in hand. The katana can talk and swiftly informs him that it is Hotarumaru, the legendary national treasure of Japan thought lost during World War II. The wakizashi is to young to have a voice, to Souji names it Sakura. This is the story of Souji and Hotarumaru's journey through a new world as he seeks to achieve ... a sword harem?

Nezumi is a girl who was raised as a hitman by the yakuza and grew up not knowing human love. An ordinary young man, Ao, knows nothing. They fall in love and start to live together, but the evil hand is close at hand.... This is a story of first love, so cruel and so sad.