From Dark Horse:
Two slaves free themselves from a slave ship; one a Japanese man, the other an African American.
After escaping, they find themselves on the shore of Edo-era Japan, a society with a strong caste system, isolated from the world. How will the Japanese people perceive this giant black man, and how will they survive? But first things first: How will they get these shackles off their feet?

The Empire of Brittania has invaded Japan using giant robot weapons called Knightmare Frames. Japan is now referred to as Area 11, and its people the 11s. A Brittanian who was living in Japan at the time, Lelouch, vowed to his Japanese friend Suzaku that he'd destroy Brittania. Years later, Lelouch is in high school, but regularly skips out of school to go play chess and gamble on himself. One day, he stumbles on terrorists 11s who've stolen a military secret and is caught by a member of the Brittanian task force sent after them, who is Suzaku. As the rest of the squad arrives, Suzaku is shot for disobeying orders, while the military secret, a young girl, gives Lelouch the power to make anyone obey any order. He takes command of the terrorists and leads them to crush the approaching Brittanian force. However, Suzaku is secretly made the pilot of Brittania's brand new test model Knightmare, Lancelot. Lelouch becomes the masked king Zero to lead the rebellion to defeat Brittania. This series follows Suzaku's side of the story, while Lelouch of the Rebellion follow's Lelouch's.

The story takes place in the same official Code Geass history as the anime, but in a different era. The title character, Renya, is a 17-year-old boy with a mechanical left arm and shuriken throwing stars as his weapons of choice. The story begins when Renya encounters a mysterious, perpetually young witch named "Reifuu C.C." C.C. has appeared in Japan's historical Edo era to seek a new partner for a covenant. Meanwhile, a mysterious man, with a striking resemblance to the character Lelouch of the original anime, also appears with unknown intentions.

An alternate Code Geass story in which Lelouch's fate is unknown after his meeting with C.C., whether he be dead or alive. Nunnally makes a Geass contract and gains the power to read the lines of the future. She also obtains a new body and takes up piloting an unusual Knightmare Frame.

A Demon wants to turn into a human because she fell in love. This is the story of her turning into a human, with, a slightly realistic view as to what might happen..... Well, only if demons were real to begin with.

From Bliss:

The powerful pirate clan Preveza holds control over the Morea Sea. Amongst the pirates is the clan's strategist, the blind but beautiful Canale, and the fleet commander, Ayace. However, the secret that Canale holds is about to change the relationship between the two of them...

The series consists primarily of short vignettes detailing the adventures of the Crossbone Vanguard space pirates three years after the original manga.
The first story is set during the One Year War and deals with a young Umon Samon. The series also features the "return" of Grey Stoke, an aged Judau Ashta under an alias, who first appeared in Hasegawa's Mobile Suit Victory Gundam Side Story manga.

From Snow Kiss Scanlations:

Towa became a sweeper admiring the legendary sweeper called, “Orange-Eyed Messiah”. The task of sweeper, which requires to “sweep” the monsters Adys is quite hazardous. On his first real attempt at fighting Adys, Towa encountered Kei, a former sweeper who saved him from being killed.
Towa asked Kei to take him as a student. However, not only Kei plainly rejects Towa’s request, he tells Towa that he saw the “Orange-eyed Messiah” die!? An appearance by a mysterious man who seems to be connected to Kei showed up with a grudge from the past. Who is he and what is his relationship with the “Orange-Eyed Messiah”? Will Towa finds out about Kei’s past too?

From Yen Press:

Rescued from the darkness by Xeno, a mysterious swordsman, Claudia the Rose Witch is the foundation of the Crimson-Shell, a special division of the Red Rose—an organization aiming to capture the results of one mad scientist’s experiments, the deadly Black Roses. But when Xeno’s loyalties are called into question, will Claudia be strong enough to believe in her dearest friend? And what is the color of the rose blooming in Xeno’s heart—a deep, passionate crimson…or a traitorous jet-black?

From Manga-Heaven:
Long ago, a devil traversed the world leaving nothing but death in his wake. Eventually the demon was slain by the 10 gods who created the world. As the people began to worship the gods, the gods created 10 swords infused with their power to protect the world from evil and peace dawned upon the world once more...
Mirim is a member of the 10 Pillars Sword Guild and one of its elite earning the title of Crimson and the right to wield one of the swords forged by the Gods. Her companion, Ash Grave, is the devil of legend. Why is a swordswoman with divine power to protect the world paired with the demon that is said to be destroying it? Perhaps there is more to this legend than meets the eye...

The people of Earth live in a society where vampires aren’t just real but dangerous. Although humanity has been able to keep them under control and even take the night away as the vampire’s natural habitat, some of them have adapted. Hesperides, a relatively new breed of vampires, have adapted over hundreds of years in order to be able to go outside during dusk when the sunlight is at its weakest and feast on humans. Aburaya Shiro, a high school kid, lives in a town where there has not been a vampire attack in years, but adults keep warning them of going outside at dusk. Shiro and his classmates take this warning lightly and head out at dusk only to find out one of their classmates who they thought they knew well turnz out to be a Hesperides. With all his classmates violently murdered, the only way Shiro was able to survive was with the help of a different classmate, Ichijoji Eruka, who doesn’t seem to be human herself.

His name is Tokijirou Kaizou, a brilliant scientist who has decided to spend his waning years taking things much easier: caring for his family, farming on his own plot of land... and transforming himself into a 2000-horsepower cyborg!?

Often makes a cameo appearance in the artist's various works including Hikaru no Go.

Tinos is the farthest colony planet from Earth. There lives a generation of people who have corrupted the dreams of the founders from 300 years ago. However, a new man will change it all...

This offbeat Japanese manga tells the action-packed tale of the Cyber 7, a team of biologically enginered robot protectors who attempt to save humanity from a threat beyond imagination.

From Easy Going Scans:

Once... Humans and Orcs peacefully co-existed, but at some point humans got greedy and started a war claiming the Orcs' territory. The diety-Lord who created all, got angry with the humans' greed and decided to punish them with 3 catastrophes. One of them was the "Dragons", divine creatures blessed with magic capable of doing almost anything. Now the Orcs, with a "Dragon" by their side, seem to have the upper hand. Will humans just sit back and see their land get destroyed? They are too devious for that... Their only good plan at that point is to abduct a "Dragon" to even things up. But how are they going to manage the capture of a being with so much power?

Note:Manhwa adaption roughly covers 2 volumes of the original novel Dark Mage (Novel).

From Illuminati-Manga:

At the turn of the previous century, the earth quaked. The earth's crust began to shift for the fourth time, centering around the coast of the Atlantic Ocean. The entire world's land mass was reduced to 3/5 of the planet, and the human population was reduced by a third. Put simply...the earth had gotten old. In 2039, there was only one country that continued to prosper, glaring around at the rest of the dying planet: Japan.

Todoroki Jin returns to Tokyo, the city where he was born, in hopes of finding his friend Ryoma. Little does Jin know about how Tokyo's changed since his last visit...

The oneshot at the end of volume 3 is called Warrior of the Holy Flame, Abi.

Recommended for fans of Riki-Oh

New cop Asuku finds himself assigned to a special unit of inhuman police agents, tracking down similarly inhuman targets. Only time will tell which will kill Asuku first, a rogue criminal... or his partner.

When a person who under goes extreme depression/anxiety, loses control, a person will become a demon consumed by darkness. Luckily there are those devoted to hunting those demons.
Boy meets monster while taking shortcut home from school, is rescued by a girl with a gun. Monster gets away. Later on, girl makes contract with boy and uses his soul energy to make a big gun and kill the monster.

From Tokyopop: Shirou's ordinary life as a poor construction worker gets turned upside down when he comes across a naked girl, Lucy, who's fallen out of the sky! Her strange and unique personality entices him and he introduces her to his apartment buddies. But after leaving for just a few minutes, he returns to the apartment to find Lucy gone, all his friends slaughtered and an ogre-like stranger standing amidst the carnage. The big man suddenly pulls Shirou out of the apartment building just before it explodes! Shirou gets pushed down into the sewage system of the city and is saved by a mysterious man...

Remember that plague you learned about in history class? Well, it's back, ready to infect hordes of people! Follow Nagasawa, a melodramatic student caught in the middle of this horrid epidemic, with absolutely no idea what's going on, trying to get through life with infected people all about. Can you say creepy?