From Kotonoha: Ayu, a 17-year-old high school student, believes neither in a future nor the happiness it could bring her. By selling herself, she tries to justify her existence, which is as bleak as her heart - it’s devoid of joy, sorrow, love. Not until her encounter with a kind-hearted old lady does Ayu begin to realize the true meaning of happiness…

From Evil Flowers:

Honey Bitter meets Kodomo no Omocha. Shuri is a private detective with a special ability to read minds. She usually handles all sorts of cases, but this time she is faced with a rather unusual request. The famous actress Kurata Sana is going to play in a new film as a detective. She wants to be able to impersonate her character as best as possible so she asks Shuri if she can stick around to learn a few things that real detectives do and how they act. Despite this childish request, Shuri also recieves a more intimate request from Sana's manager, Sagami Rei, who wants to find out the reason why Sana and her husband, Hayama Akito, have decided to live separate one from another.

Year XXXX, The Age of Chaos, a dictator meets a vampire who has awaken from 300 years of slumber and is hungry for some tasty blood.

Deep Black (a superhero reminiscent of Batman) sets out to solve the mystery of the Glory of the Seven Sages paintings. Mystery shrouds the situation and the characters as Deep Black encounters car chases, burglary cases, bomb threats, and meets Ghost, the handsome thief who escapes and slips away from DB.

Ninomae Iko, has lived in a house of only her dad and brothers, who all practice kendo. Looking to become a little more girly, she transferred to an all girls' school. Here, rumor has it, a magical cup filled with red wine will grant any wish if your blood is dropped into it.

Note: Plenty of pantsu moments.

Soran's father passed away when she was ten years old and her uncle became her legal guardian, who then left her in a nunnery. Years past and he died, and at that time, she was given two choices. One was to become a sister for the rest of her life, while the other was to get married, having no choice in which man. She chooses the latter.

Monsters descended upon the humans all of a sudden, monsters that can't be detected by most, unless they have a strong sense. An invisible predator, it feasts on humans to grow in strength and powers. 4 Death Gods are chosen to destroy these monsters and to seal the "sink" hiding the monsters fast.

From Kawaii Corner:

The strangers clad in black clothes in the organization "Death Edge". Their goal is to murder "Angels". They've killed enough people to fill the park, for the sake of thrill and adrenaline; These dark fallen Angels have landed on Earth.

Fudou Jun is a highschool teacher and takes a trip with a group of students. While there, a group of martial artists staying nearby take a strange interest in the girls.
These men are actually demons and after changing into their true form break into the cabin to rape the girls. One gets Jun and violates her.
She feels her soul being torn apart and transforms into Devilman Lady. With newfound powers and strength she kills all the demons and protects the girls from any further harm.
What are these demons and why did she turn into a hybrid of one? What does this mean for her and for the rest of humanity?

A long time ago, the Earth was ruled by demons. The demons constantly fought each other for survival, but soon found themselves fighting a new race of beings: The first humans. The demons then became imprisoned in ice after a great cataclysm. They would remain there until the ice melted, after which it was said Satan would rise and lead them in Armageddon. That time has come.
Akira Fudo, who has become the Devilman, the only being who can fight demons; a being possessing the powers of a demon and a soul of a man.

While Japan in desperate situation, 13 "devil survivors" cut deals with devils to obtain abilities to fight against unknown invaders with only 7 days left until a world catastrophe, you need to make crucial decision to survive...

From MangaHelpers: The Comp is a popular portable game system that also functions as a smartphone. But it suddenly becomes a portal for demons to travel to the human world! Kazuya receives three Comps, from his master programmer cousin Naoya, for himself and his two friends Atsuro and Yuzu. In order to survive the demon invasion, the trio have to use the Comps to summon and subdue the demon that appears in order to fight back against the waves of demons that are about to swarm Japan! [vyc]

Kinda creepy. Dante, the main character, is fighting various characters to keep the passage to the demon world sealed, but he doesn't seem to be having much luck... (And the story says 'To be continued' at the end, so there might be more to it.)

In the midst of a terrorist attack that kills all his classmates,Tohru Kuroe knows the chances of seeing yet another woman die makes Tohru pick up an abandoned gun - The beast awakens; taking over. When Tohru comes to his senses, he finds he is now a killer. Finding out he was genetically engineered to be a killer, his codename is D-17, Tohru continues his 'normal' life amidst challengers threatening his life and those around him.

From Horobi no Michi:

Clockworkers- mechanical men, created during the war as a weapon to kill as many as possible. That war may be long over, but rogue Clockworkers are still roaming about, spreading fear and death wherever they go.

Machina's a member of the CWA, an organization dedicated to the destruction of these rogue robots.

Along with Deus, her Clockworker partner, she travels the country in pursuit of these dangerous robots...

Gambling. Mahjong. Death. These are the themes of this fast-paced, undercover-agent-style manga where outrageous life-or-death gambles are made daily occurences and insurmountable odds are overcome. The most hardcore, action-packed mahjong manga you will ever see.

Included in the manga is a oneshot called Nana-chan Scrambles.

A pirate ship that cannot be sunk led by a dying Captain who will not give up. His final wish before he dies is to find the legendary Devil's Eye. And who does he appoint to lead his fearless crew in search of the lost treasure, but Olivia Soldana, a brash 16-year-old girl who can outdo any man.

Kazune joins the band KEEL and becomes their vocalist. But only after a while he is leaving to join the band BLANCA. Why is Kazune leaving suddenly? What will the members of KEEL think of him?

From ShoujoMagic:

Omori Mio is 17 years old. To help out her desperately poor family, she takes on a part-time job. Then, one night, a boy snatches a kiss from her and offers her money, saying, "I'll buy you." Who is the boy who stole Mio's first kiss...!?

An extra of S.P.Y can be found inside.