The Chrono Code, the key to a powerful weapon in the future, has been sent to 1994 and resides inside Ji Soo Jung. A gifted martial artist and the hope of her Kendo team in the upcoming national championships, Ji Soo Jung has no memory of her life prior to 4 years ago, and is searching for the lost brother she knows nothing about. She is catapulted into the middle of a violent struggle for the Chrono Code when different factions from the future start to fight over her, and she has no idea who is really a friend and who is really an enemy.

Once Demons and Humans were at war, and special warriors were needed to defend humans. Now a peace treaty exists between demons and humans. To uphold it human warriors now protect demons from other predatory demons. The Yosogi family is given this thankless task--and it's heir is young Akira, who can't even stand up against his older sister. But only Akira can sense the presence of demons, so he must become the next Demon Defender. But their grandfather has brought in a shy girl named Matsuri--and Akira is warned in a dream he must protect her at all costs!

From Dan of Population GO: Based off of The Song of the Nibelungs comes a manga about bravery, honor, and heroism. As the last of his people, Siegfried will stop at nothing until he becomes a legendary knight whose story will last eternity. If his legend lives on forever, then so will the memory of his people...and that is his sole reason for going on. 

From Fallen Syndicate:

A stylish suspense action manga depicting teenage battles!

It is the year 4088. It has been over one thousand years since the Crisis of Systems (Lost Property), which resulted in the destruction of four planetary systems, leaving only a single inhabitable planet, Zion. Mankind is forced to live in space colonies, since that one planet is constantly being invaded by alien life forms that have come to be known as Victim.

To stop the aliens and to allow people to land on Zion, mankind has developed the astronomical humanoid weapons, Ingrids, also known as Goddesses. G.O.A. (Goddess Operation Academy) is a school dedicated to the training of young men to pilot these Ingrids...

Chris Redfield and Jill Valentine arrive in a remote Russian village to check on rumors that a wolf infected with the T-Virus had attacked its inhabitants. It wasn't long before the two ex-STARS officers found them battling against the villagers, now turned into zombies.

The protagonist is a descendant of Pcell. This story happens a long time after the events of Blame!. This young silicon creature knows well the havoc that Killy brought and decides to move towards the end of the megastructure, to look for him. NOTE: This oneshot is actually chapter 8 of Blame Gakuen! and So On

Set in 2194 AD, China, which is now a prosperous, super-modern country. The characters are mostly reincarnations of warriors from the 3 Kingdoms period. The story begins in Shin Yokohama with main chara Todoroki Ranshirou driving around & causing a ruckus with his bousouzoku called Yokohama Road Stars, when he gets a mysterious package from his father. Soon after he's attacked by Blades and makes an astonishing self-discovery... that he's the reincarnation of Sun Ce!

The much-awaited sequel to BLAME! follows a man, called a Dismantler, who is in charge of sub-dividing the nexus towers that incurr Safeguard interference upon its detection of humans without the net terminal genes. Although humans are once again able to reside in the Net sphere, the Safeguard are still a threat. The Dismantler or NSE, or Net sphere engineer, goes on a journey to aid mankind in their survival. NOTE: This oneshot is actually chapter 6 of Blame Gakuen! and So On

From: Easy Going Scans

The Van Helsing Church Order is bent on destroying all supernatural creatures, as well as anyone else who gets in their way. However, a certain silver-haired man and red-haired vampire are not waiting for the Church to come to them! During their latest attack on a Van Helsing "cleansing" squad, they inadvertently save the life of a human being..

From MangaHelpers:
When an enemy explosion leaves private military soldier Terawaki Ryo nearly dead, a secret organization rebuilds his body using the research they have done in human revivals. Unfortunately for him, the technology only allows him to come back in the form of a teenage girl. His new identity, Shibahara Kyoko, leaves him distraught as his frail body doesn’t allow for the combat skills he used to have or even pick up heavy artillery he used in the combat field. Kyoko is assigned to protect a prestigious academy where daughters of powerful leaders attend since the girls’ presence makes it a hotspot for terrorists to attack and blackmail the people in power. Led by his former commander and mentor, Major Honjo who has also been reborn as Ryo, was a beautiful teenage girl named Chujo Shizuko, and the pair work together as anti-terrorist teenage school girls.

In order to determine which hot spring is to be the top overall, all of the hot springs within the region enter an unofficial tournament. The tournament is simple battle of capturing the enemy's flag, but the battle itself goes beyond any human measure. It is customary for a female to enter these battles. Carrying their pride and their flag, their only objective is to defeat their opponent. Hence they are commonly called "Fighting Spring Princesses." Kikko, the Fighting Spring Princess of the Aizen Hot Spring Temple, is an eccentric, hot-blooded person who is going to have her debut battle. Sit back and enjoy the story of Kikko's path to becoming queen of all hotsprings!

From Wikipedia:

An innocent young man, Ikuroo, has a parasite known as Baoh implanted in his brain by an evil organization, Doress. The parasite makes him nearly immortal and gives him the ability to transform into a really powerful beastie when he's in trouble.

Doress intends to use him in some sort of ploy for world domination. But while they're moving him around, a young psychic girl, Sumire (who's also being held by the organization), sets him free, and the two escape together. Of course, Dr. Kasuminome is the mad scientist behind the whole thing, and he isn't about to let his test subject get away... and he has everything from superpowered lackeys to a small army at his disposal.

Iori and Nachi are the "perfect pair" of the bodyguard agency Shelter. Partners since childhood, they bicker constantly, but when the latest mission threatens to separate them, is that really okay...?

Manga doesn't get much more noir than this. Benkei is just another expatriate Japanese arist living in the Big Apple. Or so it appears. As there "diabolical hard-boiled stories" show, surfaces aren't always what they seem. Flashbacks delve into sordid, secret past lives, and old scored, long festering, emerge without warning, asking to be settled.

And Benkei's secret? Maybe it's just that he's the only artist in town who isn't having fantasies of being a hitman-for-hire. He is one.

Bian Huang Ji, lying at the border of the south and north parties, is the only trade center where the rich and powerful people gather and illegal activities take place. In this place, laws don't exist. Whoever comes here is called Huang Ren (wild man), someone who doesn't belong to any kingdom or government. As there was no war occurring here, it's prospering and growing at an exceptional speed. However, war is like the ever-changing weather, it comes when you least expect it.

In the hopes of pleasing his childhood friend and crush, Chiharu, Arata agreed to help her clean out an old warehouse from her grandfather. But what neither of them knew was that the warehouse contained "tsukumogami", ancient objects imbued with life. When Arata accidentally broke the seal on a box containing an artifact that hungered for vengeance against humanity, Chiharu was kidnapped! Now it is up to Arata and the good, loyal artifacts to rescue Chiharu before it is too late!

Hundreds of millions of years ago, highly-advanced beings looking to make a planet for themselves purposefully tampered with Earth's natural processes in order to create multi-cellular life. Watching the planet's evolution closely, they continued to help life evolve further in the hopes of having actual civilization develop.
It's now 1996 in Seoul, where Hyesong, a high-school student, struggles with the usual problems of youth. The only unusual thing about him is that he's been having the same apocalyptic nightmare for an entire month; in the dream he is an great fighter and genius tactician who faces off against a seemingly-unbeatable foe.
Are these dreams not really dreams? Does he really have a role to play in the cosmic balance of the universe? And is the new girl in his class really just a normal student?

From back of book:

He-Sung has dreams of the Earth being destroyed by alien invaders! In these dreams he is a motorcycle-riding warrior, the last defense against the alien armada. By his side is a beautiful armor-clad girl with strange powers and futuristic weaponry. But these are just dreams, and they don't mean anything... right? That's what He-Sung thought... until his mystery dream girl appeared as a new student in his school! But if she is real... can the aliens be far behind?

The protagonist is your average, everyday, Korean school student. That is, if not for his obsession that aliens live on Earth disguised as humans.

Much to his surprise, he was right, the aliens play a game called "Avatar" where they take human form and live human lives. And because of a glitch he caused in their system, now his very life could be at risk.

Now he needs the protection of an Admin of the "Avatar game" or else he could very well die!