From Village Idiot:

Hideo Kawamura has a really terrifying look, but soft heart. While contemplating suicide, he stumbled upon this computer that contained the virus, "Wiruko", who convinced him to join the "Seimahei", a fighting tournament that has the world as its prize. However, Hideo happens to not have any fighting skills whatsoever, so he has to get through on his wits (and luck) alone.

From Easy Going Scans:

"Year 252 M.C, in this era which plants are almost extinct and the land is barren, a strange disease developed. 'Shinigami's flower,' the unique lethal flower that carries death." The disease is curable if found in the early stages but if left till transformation stage it becomes lethal and the only option left is extermination. These are all dealt with by request to 'Gokurakuen,' the national medical institution specializing in dealing with shinigami's flowers.

Our protagonist, Doctor Ichinose Souma, is the class representative of Mobile Team Unit Class 1. As his class gets too few requests, he and his assistant Hina often get into trouble interfering with other class's jobs.

"Stop your evil deeds and take the right path!" That is the creed of Youko Tama and her younger step brother, Jinka Sendou. The two demon siblings travel the country to stop the deeds of all evil doers, along with a scaredy-cat swordsman they picked up along the way, Hyoudou Shinsuke. During their travels, they will come across a monk organization with more than suspicious methods and they'll soon be at war.

From Kisu KissManga Scanlation:

One day, Natsuto found a loli near his house and it turns out she's a Holy Loli that is in a mission to eradicate the demons that escape from the Chaos Realms and as well as find the Key that can summon demons.

The Golden Dragon has sent the legendary sword into the world so that, when Black Dragon that is bound to come to destroy the world appears, a hero might take hold of the sword to slay the world-destroyer before his foul designs are wrought. Who could possibly wield the sword of legend to become the hero of legend who is fated to engage in a fight of legend with the evil dragon of legend?

As time reveals, Alfonso, an elder of the village, is and always has been the chosen one. And now, as the fated hero of legend, he must lay aside his elderly ways and stride forth on his quest of legend and find the Golden Dragon of legend so he may gain the powers of legend to defeat the Black Dragon of legend in a legendary fight to stave off the legendary armageddon.

It's going to be a legendary adventure.

Yusa Chiaki is a ordinary high-school student, whose motto is simplicity and frugality. Her favorite character is Uesugi Youzan. One day while going to search for a part time job she gets chased by kappas and a mysterious man rescues her. What will happen to her now?

This is a continuation of the Durarara!! manga starting with the Akane Arc.

Satoh Jubei, a pervert and fighting expert, has moved to a new home again started off his ridiculous school life with other interesting people. The first one he met was a girl called Ayako, who has unrealistic expectations in Tokyo life. They had some extra-ordinarily close body contact.

The series is full of ridiculous and perverted ideas. It also features some combat skills, traditional Judo vs open fighting.

From MangaHelpers: This is a manga based on a popular light novel series of the same name. Kazehaya Kamito has been summoned to the girl's school Areishia Spirit Academy, which teaches noble young ladies how to make contracts with powerful spirits. On his way, he has the misfortune of catching sight of one of these lady spirit contractors bathing. She is Clair Rouge, and she is contracted to a spirit named Scarlet, though she has her sights set on a more powerful spirit. Kamito convinces her to lead him to the school, but she stops on the way to make a contract with this powerful spirit. When Kamito ends up 'stealing' the powerful spirit, it is revealed that he is actually an unheard-of male spirit contractor! What could be the origin of his power? Now Clair is determined that he's going to have to support her, since she believes that the spirit he now has power over what should rightly be hers... [tethysdust]

A serial killer is on the loose and authorities are baffled! What they do not know is that this case requires non-traditional research methods. That's where Mako Miyoshi the detective and Kyosuke Kagami the Shikigami user enter the picture. Together they investigate supernatural crimes!

"How would you save someone when you're imprisoned?" "How would you fight for justice, if you need to break the law?" "Rui Takahashi, the protagonist found a way to solve this and tries to fix all the mysteries in his life" This is a Philippine-Based Manga :)

The fearsome foursome continue their journey west towards Shangri-La, encountering new challenges and new adventures along the way. Their legend precedes them, but not always in the way one might expect. The Minus Wave that apparently drove all the youkai in the land mad looks like it might have missed one, as Sanzo, Gojyo, Hakkai and Goku meet a lone guardian and the band of children he cares for. Fear and misunderstanding run throughout this particular leg of the journey, including between the members of the Sanzo group!

From Viz:

After orphan Teru Kurebayashi loses her beloved older brother, she finds solace in the messages she exchanges with Daisy, an enigmatic figure who can only be reached through the cell phone her brother left her. Meanwhile, Teru meets and forms a strange friendship with mysterious Tasuku Kurosaki, her school's janitor. For some reason, Kurosaki always seems to be around whenever Teru needs help which leads Teru to wonder: Could Daisy be a lot closer than she thinks?

As the mystery of Daisy unfolds, Teru also discovers that there may have been a lot more to the life and death of her brother than she ever dreamed . . . and that the man she thought was her friend just might have all the answers.

It is the 23rd century, an age of science and technology, where sex is no longer required to reproduce. However, humanity has not forgotten sex! Sex has evolved to become a form of martial arts, and those who practice it are known throughout the world as BattleSexers!

Oogami is a detective by day and exorcist by night, solving cases and hunting spirits together with his ghostly assistant Kazari. One day, a mysterious package with horrifying contents arrives in Oogami's mail, the only clue to its sender being the name of a remote village: Shirasunamura.

It's an age where aliens, monsters and other dangers threaten the Earth, and various heroes have risen to protect it. Supporting these heroes are the human defense forces, of which the sisters Kitajishi Miyuki and Yuri are a part. Specifically, their office is for hero consultation, and they help heroes solve their problems, but they also help evacuation procedures during emergencies. Yuri was formerly an immensely powerful and popular magic girl, but now she helps protect people in a more human way. In their first case, they consult with a hero who has lost his powers, and is trying to find a way to live as an ordinary human.

It is Universal Century 0079, at the end of the One Year War between the Earth Federation and the Principality of Zeon. The space colonies of Side 4, or Moore, were previously destroyed by a Zeon attack, and many colonists lost their lives. Side 4 became a shoal zone filled with the wreckage of destroyed colonies and warships, lit by constant flashes of lightning due to collisions between electrified debris. It soon came to be known as the "Thunderbolt Sector."
The Moore Brotherhood, an Earth Federation Forces unit made up of surviving citizens from Moore, set out to exterminate the Zeon forces in the Thunderbolt Sector in order to reclaim their homeland. To halt the Federation advance, the Zeon forces deployed their own Living Dead Division, which was established to collect combat data on soldiers with prosthetic limbs.
Io Fleming, though part of the Moore Brotherhood, hates being tied down by his homeland and family history. Daryl Lorenz, having lost his legs in earlier battles, is now an ace sniper of the Living Dead Division.
When they confront each other on the battlefield, they will reach a mutual realization.
These two are destined to kill each other.

From Yen Press:
No matter how much the times change, bullied kids aren’t going anywhere. And fat junior high school student Haruyuki is one of them. But one day, Haruyuki encounters Kuroyukihime, the most beautiful and elegant girl at school, who gives him a mysterious program: “Brain Burst”…and the secret of the “Accelerated World.” He may be at the bottom of the food chain at school, but Haruyuki and his destiny begin to “accelerate” with incredible speed in the virtual realm as he aims for the top.

As a child, Kasama Ryuuji watched his parents killed before his eyes by the rival, Yazuka gang. As a teenager, he finds the woman who raised him after the death of his parents, raped and murdered by the same gang. With the lost of his loved ones, Ryuuji wants nothing more to do with the Yazuka. When everything seem lost, the kind and caring, Araki, who claims to be the brother of his adoptive mother appears. Ryuuji develops a special bond with Araki but how will Ryuuji react when he learns that Araki, in fact, is the only surviving member of the Kasama gang, who has devoted his life to protecting Ryuuji. Will Araki-san, the dragon, be able to keep Ryuuji safe, or will his enemies use the young man as a pawn against him? (from MegKF by Rogue11)

NOTE: Each Hana to Ryuu Soushuuhen volume compiles 4 doujinshi volumes.

Hana to Ryuu Soushuuhen 1 (1998)
#1 Chiri Isogu Hana
#2 Hei no Naka
#3 Ryuu no Tsume
#4 Futatsu no Saikai

Hana to Ryuu Soushuuhen 2 (2000)
#5 Shinjitsu wa Yami no Naka
#6 Yomigaeru Akumu
#7 Mienai Tobira
#8 Ryuu wo Karu Mono

Hana to Ryuu Soushuuhen 3 (2003)
#9 Hebi no Rasen
#10 Kienu Juujika
#11 Karamiau Kizuna
#12 Tsuki ga Michiru Toki

Hana to Ryuu Soushuuhen 4 (2006)
#13 Kaiko to Zouo
#14 Kioku no Kakusei
#15 Aizou no Yukue
#16 Hebi no Doukoku

Hana to Ryuu Soushuuhen 5 (2007)
#17 Ai to Yami no Hazama de
#18 Yume no Mahoroba
#19 Matoitsuku Bourei
#20 Tamashii no Doukoku

#21 Tomurai no Hana (2009)
#22 Kibou no Akari (2009)
#23 Tabidachi (2010)