From Esthétique:

I heard a rumor... it's about a black box that contains all the weird and wonderful things in the world. There's nothing that the box can not do. It can grant you any wish in the world. Such a profound, mysterious story. Almost all rumors are basically like this, whether it's true or not is not important. As long as the story is interesting, everything is fine. Thus, the story begins, with a high school boy, a black box, and a mysterious girl.

Boze is about Urado Shiori, a first year in high school who is saved by a mysterious monk named Ryuudaiji. Ryuudaiji however is not your normal monk he uses modern weapons combined with spells to exorcise demons. With his Gatling gun and two automated stone lions A-Gon and U-Gon he saves Shiori from a vampire.

Cinthia is an English nun on the run from mysterious supernatural beings who decimated her home... but the only person who will provide her with refuge is a brutal dominatrix in Kabukicho, the biggest red light district in Tokyo.

From Ivyscan

Miruku gets the shock of her life when she finds a strange person in her bed one morning. Ruu claims to be an angel who has cast a spell on Miruku's family and schoolmates. In return for silence about her identity, Ruu agrees to help Miruku any way she can. One day, a student quarrels with the rest of the class. Ruu tries to put things right with a spell, but it doesn't seem to work on that student...

From Wasuretai:

For her birthday present, she wishes she could be an ordinary girl. She commutes to Rose Academy in Usuyami Town. She is Little, a beautiful 114-year-old vampire. Her brother Radou watches her, there's a werewolf servant Inukai, and the magical boy Shinji. The ghost that threatens Little's school life has appeared.

Adapted from the otome game: Princess Nightmare

From Esthétique:

Hanaka has never stayed at any particular place for too long because of her grandma's crystal ball. After hearing the news that they'll be packing their bags again, she cried herself to sleep. During the night, she heard a sweet harmony and dreamed of sleeping in a flower bed. The next day, as she was on her way to say goodbye to her friend, a trio appeared and identified her as "Princess Hanaka." They demanded the Laga Star, which she had no clue about. At the same time, a guy with silver hair and aquamarine eyes appeared confessing his love for her.

In the Renai Chuudokuteki Senjutsushi series: 1. Senjutsushi wa Kujikenai - Renai Chuudokuteki Senjutsushi 2. Senjutsushi wa Koi ni Oboreru 3. Senjutsushi wa Netsuai Sareru 4. Senjutsushi to Majin no Shiro 5. Senjutsushi to Fukushuu no Koto 6. Senjutsushi to Saiyaku no Tsubo (1) 7. Senjutsushi to Saiyaku no Tsubo (2) In a certain time, in a certain land, there was a beautiful magician with long, trailing silver hair. His name was Liu Li Xian, a man whose beauty was so great and his magic so powerful, others believed him to be not of this world. However! He had a certain "illness." Which was that he really, really, REALLY liked pretty men. He found them IRRESISTIBLE! Liu Li Xian's grand adventure in seeking out prospective lovers begins!

Tokiwa Kanenari likes to masquerade as a substitute science teacher, but he's actually in the business of dealing with the spirit world. And there are spirits in all sorts of things around him, from amber necklaces to unfinished paintings and even abandoned satellites.

The manga inspired TV drama series broadcasted in 1991.

by Nornir
Gray Town – where all the buildings are gray, except for one single house, built who knows when - the Red House.

The legendary school horror manga has been revived! Girls go hunting for mermaids to win their true love. Featuring very untraditional mermaids.

A parody of 19th-century romance, starring an eccentric Indian prince Rashanu (who also appears as a supporting character in Patalliro! by the same mangaka).

Rengo Orii loves superheroes. Other people say that his favorite, Megalith, is an old man who should just retire already, but as far as he's concerned, anything Megalith does has to be true justice. One day, a bizarre encounter leaves Rengo with the power to transform... not into an awe-inspiring superhero, but a horrifying insectoid monster! Rengo realizes that even though he might not look the part, he can still be the superhero he's always dreamed of being now, but it turns out copying Megalith's signature knee to the face isn't such a good idea when you're strong enough to kick someone's head off! Can a monster with a little kid's sense of justice really be a hero!? 

From Dazzling Scans:

In the late 19th century, the citizens of London began hearing news of a brutal street slasher and vampire. One day, Alan—a writer—meets a young woman named Marie who was attacked by this street slasher. He agrees to let this girl stay with him since she has lost her home, but ever since that day Alan begins suffering from strange dreams. In fact, Marie is a vampire! As they grow closer, Alan discovers a terrifying secret about his new friend. This is a story about love and the reincarnation of vampires.

N/A

This series is a set of several extremely short pieces: usually between 2-4 pages in length. They vary wildly in mood, character and art style, and the detail is often stunning.

Note: The manga was serialized in Kodansha's novel and manga fiction magazine, which does not targeted a specific demographic rather the general reader.

Karam's new teacher, Mr. Lee, is also her mother's new boarder. Why does he seem so interested in Karam, and why does she feel some strange connection to him? This is a story of past and present lives, love, jealousy, sacrifice, and salvation.

From Storm in Heaven:

A collection of four short stories.
Story 3: Chihiro and Chiaki are twins with a special ability; Chihiro sees strange visions triggered by the things around him, but it's Chiaki who, without actually seeing them, knows what the visions mean. The trouble Chiaki has caused by blurting out the truth behind the visions has caused Chihiro to shut himself away to keep the visions from coming. But then, one day, his brother asks him to step outside...

THE BADGUYS is a superhero comedy heist comic with a cast of characters supremely out of their depth. Dealing with daddy issues, bad breakups, decades-old grudges and profound professional inadequacies, the whole endeavour is pretty much a foregone conclusion. Badguys never win: There are rules, after all.

Yoshika and Yukina are best friends at school. Yukina is both physically beautiful and possesses a kind and gentle personality that charms everyone who knows her, including her wonderful boyfriend. Yoshika is less traditionally beautiful and has a less alluringly feminine personality. In addition, she desperately likes Yukina's boyfriend. While Yoshika does care for her friend, she is also deeply envious of her. One day, a demon in the form of a house cat appears to Yoshika and offers her the supernatural power to take whatever she wants from her friend. How far will Yoshika let her jealousy of her best friend take her?