Six members of the occult circle will spend a few days at a ruined love hotel during their summer vacation. Upon arrival they meet two additional people who join them, but in the morning of the second day, a female member was found tied & naked. In addition, the exit was locked by someone and the building became a completely enclosed cage. Will this be a repeat of the 'kodoku' that happened 3 years ago?

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)

"I can't do this!"

Yoke Feldio, A Red Mage, has left his A-rank party of five years to become an adventurer, and has finally run out of patience with his life as an adventurer. being ridiculed as a "Handyman" and "poor dexterity"!

And so begins a desperate life of joblessness....

HOWEVER! Soon after Yoke is welcomed into a party of former students, all of whom are girls! And as he conquers dungeons, Yoke's abilities are revealed one after another.

In fact, the magic and skills that he wields have a power that is beyond the norm--?

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!

A young priestess has formed her first adventuring party, but almost immediately they find themselves in distress. Luckily for her, the Goblin Slayer chose that place as his next killing grounds--a man who's dedicated his life to the extermination of all goblins, by any means necessary. And when rumors of his feats begin to circulate, there's no telling who might come calling next.

Sakra, the last surviving princess of a fallen kingdom, is being hunted down for the power of Ambrosia she possesses - the ability to grant divine strength, but only to a human. With no human companion, she decides to summon one from another world in a desperate attempt to find a knight to protect her, but the man who answers her call is less than what she had hoped for.

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.

”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 is the legendary Go Nagai's breakthrough work. Harenchi Gakuen is an elementary school whose teachers and students are all perverts. Boys peep girls changing. Girls pull up their skirts and show off their panties. Actually, it's not as evil as you imagine. They're like cubs playing together. It's only pre-school eroticism, nothing sexual. In spite of that, Harenchi Gakuen became a sensation. Parents, teachers, and politicians hysterically attacked the comic's immorality.

The manga centers on Yūma Fujikura, a constantly bullied first year high school student. When a classmate named Ryō Ameri, nicknamed "Amelie," helps him out one day, Yūma tells him not to get any more involved, or else the bullies will target Amelie too. In response to this, Amelie only tells Yūma that he would commit murder for him if Yūma wanted.

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.

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!

By the time he opens his eyes, Kubota Tamotsu (34 years old) has been reincarnated into another world. Moreover, as a 6 years old slave with “Level 1 Barrier” skill. To surpass his limitations and become a powerful Barrier master Kubota begins a hellish training, full of obstacles and struggles. — From “Let’s Become a Novelist”, a new other world fantasy starts!

Before successfully being able to commit suicide, Takeshi Hirota, a bullied high school boy is transported to another another world where he is accepted by the orcs due to his appearance.

A story of a young man who lacks a sense of reality after being dumped by his lover. He was visiting a seminar on cultural anthropology with his fellow classmates when he discoveres an ancient wall painting, which transports him to the past where mammoths dominated the world.Action

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.

Seven women, one man, a suspenseful harem story!

During a class reunion, the school became an enclosed dimension without warning. Yelling and screaming brought no response. 26-year old unemployed Haruka Sato has to survive by cooperating with seven of his former classmates. Soon, the extreme conditions began to eat away at their sanity, and Haruka's hidden desires began to take hold.

High school student Sachiko is bullied daily and is the recipient of constant unpleasant pranks in class. The culprit is unknown, however, in truth, to Sachiko those days were not particularly painful. That is because her beloved Aida-sensei is there to save her. Bright, handsome, and with a strong sense of justice, he is popular with everyone. Of course to Sachiko he is her special hero. However, Aida-sensei has a secret…

After his unfortunate death, Tomokui Kanata has been reincarnated as a member of the weakest race, a goblin named Rou. However, Rou has retained his previous life's memories, as well as an ability that allows him to gain strength and abilities from eating. He also possesses a unique evolutionary tree.

Now, Rou has made a promise to himself that he would live this life to the fullest. In this alternate world of survival of the fittest, events unfold with competent subordinates and comrades.

Orginal Webcomic

Kaede, a victim of past sexual abuse, is obsessed with becoming "normal" ...

A bittersweet story about a boy facing coming-of-age questions about love, sexuality, complexes, and other troubles.

(Source: Ganma!, translated)