His fiancee lost her parents so she will be living with the Hyeons, but Sang-Won is a middle school student and the fiancée is a 24 year old adult!? Sang-Won tries to deny that his fiancée is 9 years older than him, but seeing that she does not act her age, he then feels comfortable around her. His fiancée seems kind and innocent on the outside, but on the inside... Original Webcomic

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.

In a large mansion lives a boy, an aristocrat who was cursed by the witch to "let everything he touches die." With him is his maid Alice, who besides serving him, likes to tease him. The boy who is interested in her doesn't mind the teasing, but not being able to touch her is painful!

If they are unable to hold hands, how will their love ever bloom?

Tenkawa Toichi is a normal, ordinary high school boy, except he has a secret identity - he is a member of the evil Phantom Organization, going by the alias Wolken. They are planning to conquer the Earth, but is being met with opposition from the so-called Angel of Judgement, Mighty Heart (Who, coincidentally, is a classmate of Toichi, Maishima Kokoro). Surprisingly, Mighty Heart is so weak that even Wolken's underlings can beat her easily, but they only figure out her ultimate weapon after Wolken accidentally comes into contact with her body...

There are some humans capable of using magical power to manifest their souls as weapons and control forces beyond normal comprehension. These people are known as Blazers, and those who are recognized as such can undergo training at academies to become Mage-Knights. Ikki Kurogane is an aspiring Mage-Knight, despite being considered the worst student at Hagun Academy as an F-ranked Blazer—the lowest rank possible.

One morning, he accidentally stumbles upon Stella Vermillion, a visiting princess and A-ranked Blazer who has just enrolled at Hagun, in a state of undress. As a result, she challenges him to a duel where the loser will be the winner’s slave. It seems like a surefire win for Stella, but could there be more to Ikki than meets the eye?

In regards to the MMORPG Cross Reverie, Sakamoto Takuma boasted an overwhelming strength that was enough for him to be called the Demon King by the other players. One day, he gets summoned to another world with his appearance in the game. There, there are two people that insist, "I am the real summon master." Takuma gets slave-turning magic used for summoned beasts cast on him by the girls -
However, the peculiar ability Magic Reflection was invoked! The ones that were turned to slaves were the girls! Takuma was bewildered. He's the strongest magician but, he doesn't have any communication skills. Panicking, the first words that came out were the ones that he used inside the game role playing the Demon King!? "I'm amazing you say? Of course I am. I am Diablo... The one feared as the Demon King!"
This is the story the Demon King (acting) that would soon inspire the world and his other world adventure that he plunges through with his absolute strength, raise the curtain!

Hina Tsurugi is a first year student at a coastal high school and regards herself as an indoorsy sort of person. Walking along the embankment, she runs into an older schoolmate, Kuroiwa, who invites her to join the “Teibou” club and start fishing! Surrounded by eccentric club members, how will Hina’s high school life turn out?

Beings that create and control monsters and demons, beings that build and reign over malicious labyrinths, the chosen individuals to possess an overwhelming Unique Skill… They are the Demon Lords.

Demon Lords entice people to come to the labyrinth they’ve built and eat the people’s despair as their nourishment.

However, Creation Demon Lord Procell has decided that he will obtain people’s hopes and not their despair as nourishment, and built a happy town instead of a malicious labyrinth to collect human beings.

This is the story of an eccentric Demon Lord, with all its ins and outs.

A screwball ecchi romantic comedy about a young potential mangaka dealing with his assistants who are sisters as they are madly in love with him.

Haruomi and Yua grew up together but with puberty Haruomi begun to change, beginning taking pictures of girls annoying his childhood friend Yua! Haruomi though has a secret power awakening and their innocent relationship is about to change in many levels! A Harem × Bondage Love Comedy manga that everyone will love!

Some people with abnormal abilities invading the institute have triggered a battle for superpowered organs! Has the unknown creature been resurrected as a teenager? What is the ending of the forbidden love between the decadent bodyguard and the test subject? The truth of the mystery has surfaced a little... But the real disaster of mankind has just begun!

Mayumi lost her fiancee to the only person she called a friend. Throwing everything away, running from it all, and starting a new life in the countryside was her plan, but what awaits her is a blonde yankee, Rin (the manager of the housing complex Seagull Villa), that she doesn’t deal well with. A story about the daily lives and the relationship between these two women as well as the people in this seaside town!

Regulations and ethics are scary, but love with school girls is the best! What? A virgin cartoon editor, Kato Kazuyoshi, having a kettle and being in love with Yankee JK ‘s Nikaido Ryla (16 years old) …. Love comedy that I know but I can not stop!

From MangaHelpers:
Tonight, Natsuo loses his virginity. His partner? Her name is Rui and he just met her today after school. She's the one that brought up this whole situation, stating that she wanted to simply gain the knowledge about sex. She does not want to start a relationship, nor does she care about Natsuo.
Afterwards, Natsuo feels guilty for losing his virginity to a girl he doesn't even particularly like. Mostly, it makes him feel like he betrayed his crush to his high school teacher: Hina. A quirky love triangle story unfolds as Natsuo, Rui, and Hina all end up becoming part of the same family.

How clumsy you are, Miss Ueno

Leo, a common middle school student, was accidently invited to a Wechat group full of miracle figures, such as Lord of Thunder, Mother of Lighting, Mighty Miracle God... since then his life became totally different with wonderful equipment he got from the Wechat group.

Third son of a "beggar noble" Nore lost his job and was at a loss. But as he was contemplating whether to become an adventurer fortune struck.

A Hidden Dungeon that no one knows how to get enter. A legendary place full of hidden things like extremely rare magical beasts, magic tools for gaining power and items that would be scarce all over the world. That's the kind of entrance that was opened.

"Without telling anyone about this place I'll secretly become the strongest."

This world is harsh to nobles of poverty. Without authority of honor, if I could at least acquire power――

Mariko, codenamed "Rose Marie" is a leader of anti terrorist group, CAT (Counter Attack Terrorism). She lost her husband and son in a terrorist bomb attack at an airport. Also suffering injuries in the blast, she was left with a scar that looked like a rose flower on her chest. A summit conference is due to be held in Switzerland secretly, with Marie team deployed. However, it becomes clear terrorists have already made a move to sabotage the meeting...

The Yoshinomiya Municipal High School 2nd year students embarked on what they'd hoped was an educational trip with their friends and away from family but it was not meant to be... Their ship was hit by unexpected rough seas and crashed on a strange island! The surviving students are trying to understand what happened but soon they realize they are not alone on this island and the locals don't appear to be very friendly to strangers!!!

A man was about to commit suicide and decides to search for a way to die in the internet, but then he found an odd site that asked a lot of questions and had a point based system that allows you to create skills and abilities for a character. He took interest in it and when he finished setting his character he was asked "You will now be transported to a world with the settings you choose, coming back is not possible, do you still accept?" Then without thinking much of it he pressed YES and found himself in another world with the skills and abilities he chose to have.