From the manga habit:

Rio is a 14-year-old boy with no particular special traits, except his burning love for books. He's awkward and considered odd at best by his peers. Rio also has a twin brother, Mao. Although they look alike, they couldn't be more different. Mao is good at everything, is popular, and has future plans to have a big, happy family. Despite their differences, the brothers are close.

One day, when Rio attempts to retrieve a cat that wandered into the street, he is hit by a car right in front of his brother's eyes. Everything fades to black. In the darkness, a voice offers a choice: to live or to die. Fading rapidly, Rio gives the obvious answer: to live!

Rio awakens in a world filled with foreigners and strange animals he's never seen before. That's not the only odd thing–Rio now has the form of a black cat! He quickly learns cats are revered in this world because of their special role as familiars of wizards.

1. Yajuu Kanojo
Naruse likes beautiful things, so he wants to go out with Misuzu, but the moment he does she turns into a beast?!

2. Ookami Kareshi
Continuation of Yajuu Kanojo. This time it's Riku who becomes a beast in Misuzu's eyes. How will she cope?

3. Onnaji Mesen (Eye to Eye)
Hana used to be a lot taller than Souta. Now that they're in high school, everything has changed. Now he's the taller one with a hoard of fans as he is the ace of basketball. Everyday, the distance between the two seems to drift further apart...

4. Bianca
The androgynous second year basketball ace, Aida Leona has been confessed by the kouhai Mori Kenta. Thinking he was gay, and her disinterest in guys, she turned him down instantly. Leo had a crush on a beautiful girl she encountered at middle school, and thus the only person she ever was interested in. But Kenta is persistent, and Leo may have found a connection from Kenta, to finally find her mysterious crush...

5. Chimudondon
Satoru moves to Okinawa and is bored out of his mind because there's nothing to do. Can he find something that gets his heart pumping?

6. Boku no Kirai na Akuma (Evil Resident)
Maa-kun is plagued by a demon that only he can see! How can he get rid of it?
- Delish Scans

16-year-old Asakawa Tomoki, being a bishoujo all his life despite being male, has finally received the ulimate confession... from a vampire.

A vampire webtoon.

A bullied boy struggling with his depression possesses an unusual power to draw phantoms of evil spirit around him. Narrow-minded and timid, he has no hope for himself. Can he overcome the darkness that threatens to engulf him? Author/Artist: http://tapastic.com/ruki

The story of the "sweetie-horror" manga begins when an unnamed character without memories gets lost and arrives at a mansion. There he meets Charon, a naive girl who has a secret.

From Fallen Syndicate: By using the Dark Gate, humans can entrust their hopes and needs to the darkness. The darkness they call upon is a great and evil power, known as "Demon." WIth the help of his partner Miroku, the Demon Slayer Kisaki Senju will slaughter every last "Demon" that is called into existence.

Shingo and Kakami have finally understood their feelings and continued with their relationship, and for some reason, Kakami wants to take it to the next level by living together?

After souls die, corpses still keep their hearts. Both protagonists Inoue and Fujiwara can see those corpses whose human hearts have died. Two lonely and special people encounter each other. They are determined to rescue the people who left their soul's corpses behind and alleviate their soul's pain. This is a moving work that soothes the spiritual wounds!

It is the year 1999. In Nagano Matsushiro stands the pyramid of Japan, the private Voltstein Academy.

This place is famous for repeated occurrences of occult phenomena within its premises. Hence, it is also called the Occult Academy. The dean is committed to studying the occult, while the students are zealous in their everyday schoolwork.

One day, the dean passes away and his occult-hating daughter, Kumashiro Maya, visits the academy. There, she meets a self-proclaimed spoon-bending "time agent" from the year 2012, Uchida Fumiaki. As the two encounter various bizarre phenomena within the academy, the reason for Fumiaki's timeslip to 1999 becomes clear.

Mana is an ordinary high-school student who somehow travels through time to the Sengoku Jidai (the Warring States Period) and encounters Uesugi Masatora, one of the generals. He decides to protect her, while his rival Takeda Shingen targets her. With Mana knowing the outcome of this war, will she change the future?

On the corner of Chinatown, the two of them crossed, The boy name is Inumi Haserou, high-school bodyguard who takes 1000 yen for each trouble; the girl name is Nata, self-styled Sage who mysteriously collapsed in the back alley. Deciding to protect Nata, Haserou would have to face the sudden change in his daily peaceful lives, as a group of Vampiric being who consumed people Ki, called [Demonic Sage] starts to attack them. Their purpose: to hunt Nata, who holds the key as the powerful weapons capable of turning them powerless! Comicalization of a new series written by the Author of Rental Magica, starts here!

Set in a world where history has taken a slightly different course from the one we're familiar with. In Shizume City there is a psychic war between seven kings. The story goes that the Third King, known as the Red King, created a group called HOMRA filled with extraordinary people. If you manage to join HOMRA, you also acquire unbelievable psychic abilities.

Oneshot description:
Hinata is a human girl with a vampire boyfriend, Junya. All she wants is a "normal" boyfriend. Junya goes on a "normal" afternoon date with her, but will the sun be too much?

Series description:
Based on Mitsuki Miko’s popular vampire oneshots comes the serialization of this tale of the love between a vampire and human. Hinata was just a normal girl attending a Catholic school until she hears of the recent incidents in her area concerning a crime scene that looks like the doings of a vampire. He seems to attack only young girls, and Hinata’s suspicion begins to arise that her new neighbor Tokinaga Junya, the author of incredibly popular vampire-human romance novels, may actually be the culprit! Or, is there more to him then what meets everyone’s eye? The laws of vampires in his novels state that kisses are a contract–a contract where the vampires are only allowed to drink the blood of the one they’ve kissed! And yet, this Tokinaga Junya claims he’s never been kissed… could it be, he’s a vampire?!

A volume, Mitsu Aji Blood Tale 0, was released on 24th December 2009.

From Ryuusei no Mafia:

The Black Bard, a lonely bard who travels around the perverse and charming world. Who will be delighted by his voice? What is the mystery surrounding this bard? This fantastic adventure told in the way of the bards, filled with mystery and intense drama, begins now!

From Viz:

Shurei Hong, destitute but of noble birth, has always dreamed of working as a civil servant in the imperial court of Saiunkoku, but women are barred from holding office. The emperor Ryuki, however, refuses to take command, leaving everything to his advisors. Shurei is asked to become a consort to the emperor to persuade the ne’er-do-well ruler to govern.

Shurei enters the palace as Ryuki’s consort, but he has yet to seek her out. It is rumored that men, not women, share the emperor’s bedchamber. Shurei must think of a way to stop the emperor from shirking his responsibilities, but she has to find him first!

From Fateful Encounters:

Four years ago, Prince Lulnavul fell into an eternal sleep due to an unknown curse. The king then made a proclamation: whoever wakes the prince will receive any reward they choose... but up until now, not one has achieved it. Now, Witch Sayla, scorned by the outside for being a witch, attempts this task as the 99th contender, not for the sake of the prince's hand in marriage like the princesses before her, but solely for the king's national treasure, the Sapphire of Illusions. Can a witch, who is hated even in fairy tales, be the heroine of this one? Follow Sayla as she goes to meet this sleeping prince inside his dreams.

From MangaHelpers:
Multiple instances of mysterious mass deaths are erupting all over the city. The only similarity between each mass death is the time in which the victims were found dead. Trainee doctor Sasaki finds himself in the midst of one of these mass death events. He must now fight his way out of a dungeon ruled by a man-eating monster: "Hitokui." As other humans are slaughtered and eaten alive around him, will he be able to escape out of this dungeon and bring an end to these mass murders?

Suzuka got a tarot card reading from her friend Miyabi that she will meet her love. Could that be Konno, the guy in class D who confessed to her a year ago when they were in the same homeroom class? But before Suzuka could realize her feelings, Konno...?!

In the Abe Seimei Koikatari series

V.1 - Hana no Utage

1. Feast of the Flowers
Ming became blind after an unknown illness two years ago. One night, she meets a man in her dreams who restores her sight. She falls in love with him, but how will she find him again?

2. The Girl Among the Moonlilies
A princess chases a firefly which leads her to a man. She is so surprised by him that she steps backward and accidentally falls over a cliff, losing her memory. What will happen to her?

3. Moon's Dew; Star's Tears

4. Winter's Bloom

V.2 - Hanakanmuri no Hime (The Flower Crown Princess)

1. The Golden Phoenix, the Silver Phoenix
A princess longs for a lost love and almost loses her life until a mysterious exorcist opens her heart and mind to the truth and to what has been right in front of her all along.

2. The Hime with the Flower Crown
A young princess learns with the help of a mysterious young boy that putting away childish things may ultimately lead to a fulfilling new world and to the fulfilment of her beloved father's wish.

3. Memories of a Flower
While trying to solve the mystery behind the ghostly apparition of his beloved princess, a young man learns to ease his own sadness.

V.3 - Hanaemi no Otome

1. Hanaemi no Otome
A daughter of a high status man is being cursed by Douman, a man with strong spiritual power. Abe Seimei is set to save her.

2. Kaze no Hatsune
Story of young Douman's love, and also of how he met Seimei for the first time.

3. Tsukimiya no Maihime

V.4 - Hana Akari no Yakusoku