A lamb surrounded by wolves gets a guard dog. But is the guard dog the most dangerous wolf of them all?!

This is a oneshot from the manga Ijimerarekko.

Suwa Daisuke is an ordinary, but popular, high school student. One of his classmates, Aikawa Hinako, is somewhat fearful of men and because she ran away from just his attempt to touch her hair, he states to one of his buddies, that she is the only one he wouldn't date, unaware all of the people in his classroom could hear them, including Hinako.
Daisuke's attitude changes after he unintentionally hears a shocking truth that she confesses in an abandoned church. His former annoyance turns to compassion and concern. Hinako is unaware that he knows her 'little' secret. Believing him to have no romantic interest, she becomes more relaxed and comfortable in his company. Their relationship faces a lot of obstacles, including jealous classmates.

In the days of war, a baby fused together with a "shadow" called Blue Dragon, a legend among the "shadows". Because of that, he was locked in darkness from birth until recently, 15 years later, to prevent his shadow from activating. From the beginning, the only person he knew was his tutor who would come see him everyday. But "shadows" have begun to run rampant as they escape from "Noir" through living beings. Humans call for the release of Blue Dragon in order to help mankind; thus their journey begins to seal the "shadows" along with the strongest: their queen.

A slightly different telling of the hit manga " Boku wa Tomodachi ga Sukunai." It still follows the same concept as making a friend making club. If you enjoyed the original you probably will like this.

The Otohime Private All-Girls High School is a very prestigious school and full of pretty girls. However, there is one male student attending the school, the director’s son Ouji. Ouji is a creepy pervert who can get away with anything because his father doesn’t punish him. He’s got video cameras all over the school to get footage of his classmates naked or near-naked and constantly sneaks around with cameras to get photos of them. The school is his paradise.
All this will change in the coming year, though. His father has decided to make the school co-ed, but with only baseball players so that they can aim for winning the National High School Baseball Championship at Koshien Stadium. In preparation for this grand dream, the director insists that the girls of the school establish a cheerleading squad. Seeing his glorious world collapsing around him, Ouji latches on to the most hopeful thing he can find: the cheerleading squad. Now he and the reluctant student council president, Itsuki, are going to recruit members and try to get this team going.

From MangaHelpers:
After high-schooler Nanatsu Io is crushed by disappointment in love, she finds herself pulled into a strange cafe, "Cafe Acheron," by pretty male workers, Kiba and Resato. Io decides to change herself by getting a job there as a waitress. In order to do so, she makes a contract with the cafe owner, Kiba, who tells her she must keep her stuffed bear (now conscious and referring to itself as "Father") with her.
It's only after this contract is formed that Io begins to learn the truth! Cafe Acheron connects the demon world and the human world, and it's there that many deals between demons and humans are made. In fact, Kiba and Lesath are demons themselves, and Io is already bound to them by contract! Her strange new life is just beginning.

Takumi is a high school student. He is withdrawn and is not interested in 3D things. In his town, a mysterious serial murder case happens and people get panicked. One day, when he chats on the internet, a man suddenly contacts him and gives him an URL. He goes to the website and finds a blog image that suggests a next murder case... On the next day, it really happens... Takumi Nishijo suffers from intense delusions as a result of his apparent schizophrenia and the extremely secluded lifestyle he lives as a hikkikomori. One day he accidentally stumbles upon a gruesome murder scene, a part of a chain of events called "New Generation." After this, his life gets caught up in these events, and he meets a bunch of increasingly insane anime girls with swords.

Chaos;Head's story is set in 2008 in Shibuya and is centered around Takumi Nishij?, a high school student at the private Suimei Academy, and the strange and brutal murders that have recently occurred in the Shibuya area, known as the "New Generation" (????????????) Madness. The story begins on September 28 with Takumi talking to an online friend called Grim (??? Gurimu?). Grim is trying to bring Takumi up to speed about the recent New Generation events since Takumi is not interested in local or international news. A person named Shogun (???) joins the chat room midway through Grim and Takumi's conversation. After Grim leaves the chat room, Sh?gun begins to talk. He speaks in a very cryptic and confusing manner, leaving Takumi nervous. He then sends Takumi a barrage of image links, one of which appears to be of a brutal murder of a man being pinned by stakes to a wall. The next day, Takumi comes across a real life murder scene. Witnessing a mysterious pink-haired girl pinning a man up by stakes in an alleyway, he immediately realizes he is witnessing the very murder detailed in the pictures he received the day before. Convinced Shogun is targeting him and the girl he saw committing the murder is somehow connected to him, Takumi tries to avoid getting involved with other New Generation events. However, as Takumi begins attempting to distance himself from the crime he witnessed, he soon catches interest of the police. With the police suspecting him, and himself convinced that he is being targeted by Shogun, Takumi finds himself caught in a spiral of delusions and paranoia, as he desperately tries to keep himself safe and figure out why he is apparently being targeted. He eventually comes into contact with several other people related to the events, including the girl he saw committing the murder herself. Unsure of what is real or who he can trust, Takumi finds himself thrust into a much larger scheme than he ever thought possible, as the mysterious company NOZOMI carefully plots something from behind the scenes. From Baka-Updates: Takumi is a high school student. He is withdrawn and is not interested in 3D things. In his town, a mysterious serial murder case happens and people get panicked. One day, when he chats on the internet, a man suddenly contacts him and gives him an URL. He goes to the website and finds a blog image that suggests a next murder case... On the next day, it really happens... Could he be really the one responsible? And where is the D-sword that he is supposed to find?

In this school fantasy story set in the distant future, creatures contaminated by pollution have overtaken the land, forcing humanity to live in isolated mobile cities called Regios. One such city named Zuellni is a self-contained school in which freshman Layfon Alseif has just enrolled. Layfon reluctantly joins the 17th Martial Arts Studies Unit led by the third-year student Nina Antalk and embarks on a series of adventures.

This version recounts a slightly different version of Layfon's story.

From Tokyopop:
The plot centers on Kazuki Sendo, whose passion and talent for painting and drawing propels him into the world of doujinshi (underground comics). Soon, Kazuki's everyday life is consumed by the fanboy life and his girlfriend is beginning to have some serious doubts about him...
Sure, his new career as a struggling artist has begun, but at what cost to his friends and family?

This is a manga adaptation of the otome game Clover no Kuni no Alice that focuses on Alice and Gray.

From Seven Seas:

From the time she was sold into servitude as a young girl and told by a handsome demonic figure that she had a destiny to fulfill, Sheila’s childhood was anything but easy. After joining an assassin’s guild to undergo rigorous training, Sheila is later taken in by the dashing Prince Edvard to serve as both his housemaid and bodyguard. As skillful as she is with a blade, Sheila hasn’t a clue when it comes to courtly romance. While she uses her talents to help Edvard win the throne, can she stave off the many admirers who vie for her heart?

April 10th. Yesterday was the last day of spring vacation, so starting this morning it was a school day. After being woken up by his cute little sister, Itsuka Shidou believed that it would be the start of another normal day. As for predicting the chance meeting with the girl who called herself a spirit...... Along with a sudden shockwave, the townscape vanished without a trace. In a corner of the street which had now become a crater, the girl was there. "�”You, have you come to kill me too?" She is the disaster that will destroy humanity, a monster of unknown origin, and a being rejected by the world. There are only two ways to stop this girl: annihilation, and conversation. His little sister Kotori, wrapped in a military uniform, thus said to Shidou: "Since it's like this, just go date her, and make the spirit fall for you!" "Wh.. whaaaaaaaat!?" Enter a new age of boy meets girl!!

Republic of Biscotti faces a predicament by the invasion of Galette Leo Knights. In order to save the country, Princess Milchore summons a "hero" from the outer world. Shinku, a junior high school boy living in the Earth, is chosen as the hero.

*This series contain side stories to the anime series that take place before the series, in between some episodes and at the end.*

Nishimura Akuji is an ordinary middle school student, until one day he gets a phone call from the Angel Realm. He's been chosen at random to be a Witch Trial Judge! He meets his new "master," a tiny angel named Lulu, who explains that their job now is to find the God Witch hiding somewhere in town, or risk her taking over the world. Using various methods, Akuji and Lulu have to hunt down suspected witches and subject them to decidedly embarrassing trials in order to expose their true forms. They're going to need all the help they can get before they run out of time!

Noya Itsuki just started his school year at the Ebisugawa High School and since he has always had a fascination with space, he decides to join the astronomy club. However, he mistakenly walks into the all girls Otaku Club. He notices that the members are really weird, but Itsuki has yet to realize that he isn’t in the astronomy club. His life is about to get complicated by being surrounded by so many girls.

From Spoils:

Engage – a covenant pledged between knight and noble

This is the tale of individuals tied together by the sacred bonds of Engage

Tia is a young girl who hails from the remote regions of the Grunwald Empire. Due to royal decree, she is required to attend a prestigious academy located in the imperial capital. The academy serves not only as a networking spot for the children of aristocracy to meet and rub shoulders, but is also where the paths of nobles and knights cross.

Tia herself is on a mission to find a knight with great promise, however, who she stumbles upon instead is the academy’s problem child – Duran. Due to an encounter with Duran, Tia finds she is able to draw out a knight’s potential, normally only done via Engage. As someone who can call forth the powers of Engage without a pledged covenant, Tia finds herself the target of many knights…

This series has been on hold many times, and now the author has decided to stick to volumes instead of serializing. From Tokyopop: Welcome to Faeries' Landing, a place where the real world and the faerie realm collide. Sixteen-year-old Ryang doesn't realize that supernatural beings descend on his town at night, but when he stumbles on a group of faeries bathing, he ends up becoming guardian of Fanta, a grounded--and very fetching--faerie. Having an otherworldly babe hanging on you 24-7 doesn't sound so bad at first... but when Fanta’s rival curses Ryang, he is destined to encounter 108 doomed relationships...

Hina has repeatedly transferred schools due to her father's job, and has always dreamed of a normal high-school life. At her new school, however, she finds that her class is comprised solely of guys! On top of that, five mischievous boys from her class have taken a liking to her...!?

Three quarters of the world is the world of the dead. The world has been invaded by phantoms. One day, a boy named Nagi finds in the mountains of scrap wood a mechanical teenage maid girl. He immediately takes her home to repair her. The first things that Elise, this mysterious mechanical maid, says is, "Good morning, Nagi." Who is this mysterious silver haired girl? The fate of the world rests in their hands.