The continent of Halkeginia is tumultuous--a place where the various kingdoms, princedoms, dukedoms, and fiefdoms strive against each other to expand their domains. They nobility scheme and plot among themselves to gain influence to their lieges or to even foreign lieges. In the middle of Halkeginia is the small but important kingdom of Tristein. The most notable fact about this kingdom is the Tristein Academy of Magic where nobility from all over the world come to study magic so they can become magi. Although friendships will form across national boundaries at this school, will they survive the politics and games of the world at large once they leave?

Louise is a student at Tristein Magical Academy. She is known to be quite a screw up when it comes to her magic. One day, a ceremony takes place where each student is to call forth a being or entity that will become his or her familiar. For Louise, her familiar comes in the form of a boy named Hiraga Saito. Somehow, he managed to get transported from his world into hers, and shortly after became her familiar.

Daisuke Aurora works with the special division of peacekeepers in the city of Jewde, one of the largest cities on the planet. He and his android partner, Heat Guy J, team up to make sure that anything illegal stays off the streets and out of circulation.
However, their presence doesn't sit too well with the local mob leader--a ruthless, unbalanced, well-armed son of the late Don, who is out to prove that he is not too young to take over the family business. In the city that never sleeps, will Daisuke and Heat Guy J end up sleeping with the fishes?

Yugo Beppu is a master negotiator and mediator. Fluency in five languages, Socratic wit, and a deep understanding of human nature combined with top-level international connections make him a formidable operator. When a woman's father is seized by Dacoit bandits in Pakistan, Mayuko seeks Yugo's help. After complex and dangerous negotiations, he secures his release. After this success Yugo is called in to deal with yakuza in Japan, triads in Hong Kong, the IRA in Northern Ireland, and the Russian Ministry of Internal Affairs in Siberia.

Note: New versions of this manga were published under different arcs in bunko format such as the Pakistan Hen, Russia Hen, etc.

From: Easy Going Scans
High-school student Jinpachi Kogure is a member of the manga club and is no good with women. Yumika Testuyoshi is a troubled female high-school student who's always skipping school and searching for a girl she doesn't hate. However, these two are in reality young masters of the art of killing people:"Young Guns.

The main protagonist, the shy Jun Naruse, is a rather average guy who works for a electronic company and loves to draw. He falls in love with Megumi whom he met at a shop selling drawing materials and an intimate relationship develops. A few days later the office gets attacked and when the criminal tries to shoot a little girl he saves her by jumping in front of her.

A month passes until he wakes up again and is told that half his brain got destroyed and he only survived because someone donated half a brain. Everything seems to be fine, he quickly recovers and is happy, however he begins to change... is the donated brain the reason for that? Or is it just a side effect of the medicine?

One-shots included in volume four:

• Area
• Yasokyoku - Nocturne
• Body

The shogunate installed by the Tokugawa is abiding order, the people live in peace and in a relative prosperity.

However, the dark part of the human heart does not cease to arouse their cupidity : it is the ideal doorway for all demons that, by possessing humans, seek to pass into their world.

Exorcising these demons is Jonosuke's mission, the master of keys. Known for being the best locksmith of Edo, Jonosuke uses particular locks to put the wicked spirits under lock and key. With the help of the bewitching O-kin, a divine who uses unorthodox methods, Jonosuke is going to meet during his demon hunt some notables of his time, who will prove to be precious allies when he faces a plot aimed at the upper spheres of State.

A spin-off of Working!! Collected as part of Working!! volume 10 during tankobon release.

From Shinnen:

There are rumors of a grand treasure located within the local museum of Ashiwara and that this treasure requires a special key to unlock. But no one seems to know what this treasure is or even what the key looks like.

But Kei and Hikaru, two childhood friends, may inadvertently find out when someone seeks to claim the treasure for themselves and that action plunges their world into chaos.

From Manga Jouhou:
Takashi Sone is living on his own while he is attending college. Out of the blue, his parents tell him that his sister, Mafuyu, is moving in to live with him and that she will be attending a high school in his area.
When she arrives, he finds out that she was kicked out of her old school for getting caught making out with another girl. Soon afterwards, the other girl arrives, having thrown away everything she owns in order to run away and live with Mafuyu.

Volume 11 has a unreleated 2 chapter story at the end called Frills

Watanabe, an alien student from 20,000 light-years away, comes to homestay with the Tokino family to gather material for his thesis on Earthling behaviour. He follows around the various family members asking mostly funny but sometimes profound questions about their work, their loves, their polluted air... When he's not being sent on errands or punched in the face, at least.

Yoshiaki is entering a school that is famous for its fights and violence. He chose to go there for just that reason, and he intends to be the strongest one there. When he first arrives, he helps out a girl called Homura, who is being picked on by some guys. When she asks him to be her "sword" afterward, Yoshiaki doesn't know how to respond. Apparently, students of the school team up in pairs; a "sword" and a "master". Others advise him not to associate with the girl, who is a "Rank F", as she probably won't live very long. However, Yoshiake is not thrilled with the idea of abandoning her to die.

The year is 2008, and Mikuru is a 16-year-old high schooler who often disagrees with her mother Yuki. One day a girl appears in front of her with toughts, memories and body are from 24 years earlier. In short, Yuki has time-slipped from 1984 to the present, and when Yuki wakes up she is shocked to find that the year is not 1984, and that Mikuru is her daughter.

Now both mother and daughter are the same age and living in the same house together, with an older man who is supposed to be her husband. Until when she can return home, the girl who has crossed space-time decides to discover her future.

On a trip to look for his brother, a hungry Hachiya Rei stops at a shrine to pray. It is just his luck that he is accused of stealing money from the shrine and forced to work to pay off the amount stolen. However, the real thief turns out to be a daemon, or a god turned evil! An encounter with the daemon unleashes Kagutsuchi, the god of fire, concealed in Rei. As Kagutsuchi's proxy, Rei can use the god's holy fire to purify daemons, but there's a side effect...

Only the strongest woman is worthy of being Queen. On this continent, a desperate struggle to crown the new Queen is held every four years. The Queen's Blade.

Lucius Lucent is a cold blooded female warrior that makes men in battlefields quiver in fear. Along with her magical armor, Gil, she destroys everything in her path with her overwhelming power.

In a city split between humans and occult, Colin Aston just wants to run his diner and make bad coffee. A peaceful life isn't on the menu though, as a mysterious blonde shows up with a job only Colin is capable of performing. If he takes it, Colin will have to face sorcerers, politicians, and little old ladies... not to mention a secret that destroyed nearly half the city and hits a little too close to home.

Explore the lives of the famous-yet-not-so-famous people of history; such as Nikola Tesla, Ty Cobb, Typhoid Mary, the woman behind the Winchester Mystery House, Kou Yoshio, and many more.

Series of one-shots published between 1989-2003, released a tanko volume in 2004 and a bunko release in 2012.

Pineapple Army is a story about a legendary Japanese ex-mercenary, working as a self-defense instructor. He is sent all around the world for a job by an international self-defense agency, and in each episode, there is a human drama. Along the way, he also saves the world a few times from the hands of terrorists.

From Brolen:

This is a horror/sci-fi story about a giant planet consuming creature from another dimension that a scientist discovers and mistakenly identifies as a planet. Being given the honor to name it as its discover, the professor chooses to name it after his only daughter, Remina, but when Hellstar Remina is headed on a direct collision course with Earth the world goes nuts and all the people in the city start a witch hunt to kill Remina, thinking she is somehow to blame.

Hellsing, an organization devoted to the elimination of the vampire threat, has recently uncovered information regarding the attempted production of "man-made" undead. The world is presently in the thick of WWII, and the current leader of Hellsing fears the Nazis could potentially use these creatures as front-line super-soldiers. Although the technology of creating artificial vampires is still in its infancy, it has advanced enough to be a serious threat. In an attempt to put a stop to this perverse and dangerous experimentation, Hellsing has sent two of its most skillful agents to Poland. A young man by the name of Walter C. Dornes - a.k.a. "The Angel of Death," and Alucard, an ancient vampire currently in forced service to the Hellsing Organization. Together, they attempt to stop the progress of the Nazi's efforts.