From Village Idiot:
What will happen to an ordinary human teacher who falls into a youkai school, with his only ally(?) a sexy but air-headed nekomata? A slight ecchi and heartwarming read brought to you by the author of “Sore wa Totsuzen, Unmei no Aite ga”

A short story about a cat demon and a teacher.

Loner high school student Moribe Kyouya thought he was lucky to have the beautiful and mysterious new transfer student Baroque talk to him. The next thing he knows, he receives a love letter calling him to the roof, but the confession isn't exactly what he expected...

Atori has an unusual part-time job... she’s a demon hunter! After school, she hunts demons for a mysterious organization named N.U.E. To kill her enemies, she unsheathes the saber hidden within her hair. However, Atori is actually half-demon, but she has forgotten her past. Despite this, she's been able to overcome many difficulties as well as befriend those from both species. Unfortunately, her once calm life is beginning to quake as a terrible shadow now looms over her...

Late one night when Jun was out on his bike, he came across a drunk, half-naked girl sprawled on the side of the road. She came to just enough to be uncomfortably affectionate, but Jun took her to his home to sleep it off with gentlemanly discretion. It turns out that she is Kawase Narumi, his author mother's new assistant. Unfortunately, she has no idea what she's doing in her new job, so Jun's going to have to coach her. He's also going to have to deal with her habit of getting drunk, mostly naked, and cuddly. Jun's life will never be the same! [From Baka-Updates]

Kyousuke wants to be a cop. Because of that, he always tries to do the right thing and help others out. Well, while saving a girl from some bullies, they end up liking each other. Not to soon after, she needs saving again, and he ends up with woman's panties over his head, giving him super strength (pumped with horniness.) Not your normal super hero.

Yona Ryouma, a normal high school boy, saves a man from another world at the cost of his own life when a mysterious earthquake occurs. The man, Emillio, uses a potion which apparently saves Ryouma's life. However, he is also changed into a girl in the process.

Emillio is actually the prince of this alternate world and he declares Ryouma as his wife, presumably on the context of saving his life. But what about Ryouma's life as a high school boy in his own world? And will he come to accept being the prince's wife?

Goto Nagi has travelled to the southern island of Okitsushima, and ventures out to see Umi no Misaki, a striking cape jutting out into the ocean. But when he arrives, he finds that there is much more to this cape than a wondrous view. There is something peculiar about the cape, and about the island's inhabitants.

This adaptation focus on each heroine based on the Amagami visual novel.

V.1 - NANASAKI Ai
V.2 - MORISHIMA Haruka
V.3 - SAKURAI Rihoko

Read some slice of Asuka-chan's normal life. And see how interesting some daily activites of a cute high schooler girl can be.

Yukinari Takase is a huge masochist who instantly takes a liking to Rion Tachibana, a menacing trap who just transferred into his class. After Rion believes Takase has uncovered his secret, he decides to make Takase his servant in order to keep his mouth shut.

In the 30th century A.D., in a world in which magic exists, 100 years have passed since the human race won a war against the Devil King. Even though the war caused many sacrifices, slowly but surely civilizations began to rise again.
One day, a virtuous child named Sai Akuto ("Worst Evil") is adopted from the orphanage he's lived in ever since a witch quietly left him at the church as a baby.
Five years later, Akuto passes the test to enter Constantin Magic High School. But after arriving and taking the vocational aptitude test, Akuto receives surprising results:
Examination Numbers: Number 021
Name: Sai Akuto
Future Occupation: The Devil King

Loser Yarahata Kanji can't even have a normal conversation with a girl let alone have any kind of relationship with one. But one day a ghost named Aiya appears and declares that he has been tasked with the mission to change Kanji's life. At this rate, the Yarahata name will not live on so Aiya will become a love doctor and coach him on how to develop relationships with girls.

The first hurdle comes when he starts a part time job at a convenience store and sees that his co-worker is a hot girl named Yoshizato Saki who also happens to be the store owner's daughter. With the help of Aiya, Kanji, although stumbling along the way, has a conversation with her and builds a relationship. But he has miles to go if he wants to be the kind of person that can date beautiful women.

School girl is trained by a secret branch of the police to detect and to kill demons disguising themselves as humans.

From Infinity Studios:

When you're the most notorious delinquent at school you have one hell of an image to maintain. The last thing you need is to be seen taking orders from an innocent puppy-eyed girl. But unfortunately for Keiji Sendai, he finds himself in this exact predicament when, Setsuna Yatsusaki, the shyest girl in school (as well as being the biggest klutz) finds out about Keiji's deepest and darkest secret... that he's a hardcore otaku! With her new trump card, Setsuna blackmails Keiji into becoming her slave. But just how long can a weak naive young girl keep such a dangerous young man as her pet dog? Join in on Setsuna's secret as she sets out to "train" a notorious thug in this unorthodox love story.

Note: Was originally serialized in Dengeki Teioh magazine in 2005 as "Kyouhaku Dog’s". This run ended after the magazine became defunct in 2006.
Serialization restarted in 2010 issue of Dengeki G's Festival! Comic under the title "Kyouhaku Dog’s - Another Secret".

Jung Yoon-hwan may be an orphan but he was a college student who was focusing hard on his studies, one day he is brought to a mysterious "White room" to fight even when he does not want to. Every time he defeats these monsters he gains psychic power, magic, and items beyond his imaginations....

(Source: Game of Scanlation)

First year high-school student, Toujo Basara, is now living with two beautiful step-sisters thanks to his eccentric dad. But Mio is actually the new Demon Lord and Maria's her succubus chaimberlain. Throw in a "reversed contract," rival demon tribes, and the ecchi situations mainly brought on by Maria for good measure, and you have a situation where Basara's life will never be the same. This seinen adaptation of the light novel mostly focuses on the said latter ecchi situations that occurs between the three main characters.

A S class leveled witch family has finally gotten a baby with extremely high amount of magic. But, why is it a boy? As your mother, i can only raise you to live like a girl.

Seikyou Private Academy, built on the intrigue of traditional occult myths, bears a dark past—for 60 years, it has been haunted by a ghost known as Yuuko, a young woman who mysteriously died in the basement of the old school building. With no memory of her life or death, Yuuko discreetly founds and heads the Paranormal Investigations Club in search of answers.

After a chance meeting leads Yuuko to cling to diligent freshman Teiichi Niiya, who can see the quirky ghost, they quickly grow close, and he decides to help her. Along with Kirie Kanoe, Yuuko's relative, and the oblivious second year Momoe Okonogi, they delve deep into the infamous Seven Mysteries of the storied school.

The 15th Hierarchical City of Torifune is best known as the Military Academy for the NOL. There, future librarians train and hone their skills for whatever challenges may await them outside. The story centers around Mai Natsume, a girl who had just arrived late due to a week absence, but there seems to be several phenomena centering around her that could be more than just coincidence.

Japan: the Gambler's Paradise! The rich and beautiful Maria is well-known as a legendary gambler who will take on any challenge, no matter how unreasonable or impossible! But what happens when she meets a lowly slave who solves her riddle..? Twist after twist! So tense you'll forget to breathe! This MangaBox-exclusive five part gambling story will leave you aching for more!

Prequel: Once Upon a Time