Masumi Takanagi is normal 16 year-old boy, that is until one night, he dreams of an mysterious man cutting off his hand with a scythe. Then he wakes up to the sound of his alarm clock, and finds his hand bleeding. Now strange things are happening and his seemingly woundless hand continues to bleed. What will become of Masumi and his mysterious hand?

From The Zero Alliance:

A young girl called Ene is searching for her parents? killer, Estoma. Her search leads her to a strange gravedigger called Mal, who she works with to find out a way to kill the immortal Estoma.

Lily Liemola is a powerful swordsman with rather old-fashioned ideals about honourable battle. When he hears of a "legendary fighter" named Albert Wilhelmus who many skilled combatants have failed to even approach - let alone defeat - Liemola wastes no time in challenging this man to a duel.

A touching story of a doctor who wanted to help people even though he became a vampire.

In an future apocalyptic world the church once again has regained power, but not to do good, but to serve evil. Cloned priests, called "dragon fly" of the kirihito church use their power, however a shinigami has appeared to stop them and reclaim her past...

A collection of Dragon Kishidan oneshots and side stories:

One Day, Another Day
Set before the end of the series, it's basically a side story of a day in the Dragon Castle, kind of in Zoma's perspective.

Juuji ni Hikaru Hoshi
Takes place before the events of the actual series. This is a back story that shows how Lykouleon and Raselane met, introducing Lykouleon's uncle, Fieruto.

Mamono no Mori no Kioku
Another backstory that delves a little bit more into the relationship between Bierrez and Cesia before the series started. It also shows how Nadil became the demon lord.

Happiest Children
This actually has three little side stories in it. The first one is about Rune's dream about everyone dressed in drag, the second is about a little adventure that the three dragons go on, and then the third is like a day in the life of Alfeegi, Ri-ma, and Duma.

Crescendo
Backstory about how Lykouleon and Kaistern met and how Kaistern then became the Blue Dragon Officer.

CONFESSION - Thats
This is basically the backstory of Thatz and how he knew about Rath's little secret.

CONFESSION - Rath
Basically telling a lot about Rath, particularly his relationship with Kaister.

From Iskultrip Scans:

In order to restore the Great Dream Tree of Elfland to life, Kiki, a mare, has to eat bad dreams that plague people’s hearts and foster good dreams so that they sleep well. Aided by Gilly, the tree guardian, and the garden elves, she wanders the human world. However, the world is a dangerous place...

Volume 1: Dream Eater
Volume 2: Dream Eater - Saigo no Yume

From DrMaster:
After his mother's death, Kuro Takagi transfers to Yotsuji Private High School where his father is the proprietor. But Yotsuji is no ordinary school. It holds a strange rule of “No students on campus after dark!” On his first day of attendance, Kuro and his classmates inadvertently break the school’s highest protocol and find themselves victims of a faculty zombie attack. Although they manage to narrowly escape, this is but a prelude to more encounters with the undead, especially after Kuro discover his own blood-ties and latent zombie abilities. From there, it's full steam ahead as this dark and intense action/comedy shifts into high gear.

Once upon a time there was a king who ruled by fear. Upon discovering the existence of the Goddess of Destruction he resurrected her, but this only lead to the destruction of his own country. As a result of the carnage, she was sealed in a box that was kept in a very deep, dark place. The box was locked with many keys, keys that were then spread across the world. Many years later a Samurai discovered the box and decided to challenge the Goddess of Destruction, but first he had to gather all the keys and fight through hordes of undead soldiers. Can you really defeat a Goddess?

Juju doesn’t remember anything – not even his name (it was the writing on his coffin) – and yes, he’s already dead. But he’s been revived and introduced to Liila – a girl with prehensile hair and his right hand has been replaced, so there must be an adventure ahead!

(From NatsuYume ver. 1.)

Above the Earth, there is a continuous battle between angels and devils. One devil in particular, Sword, has it in for a certain angel, Ios. In their 101st fight together, both are severely wounded. Not only that, but their clashing power causes the two to fall to earth. By chance, Sword finds a beaten, unconscious teenage boy nearby, and he is able to take over the human's body to save his own life. Some time later, Sword awakens in the hospital, briefly confused about his whereabouts. The father of the body he possessed enters the room, extremely happy to see his boy Souma alive. Then the older twin brother shows up. Immediately, Sword recognizes his enemy's energy. Also nearly dead, Ios had joined with Kanna's body. Sword goes to attack Ios, but quickly realizes that the body is far weaker than his demon form, especially from being recently beaten to hell. Since the brothers had been found heavily thrashed, their memory loss isn't that surprising. Their large change in behaviors is also explained by amnesia. As it turns out, Sword entered the body of the cliché nerd who can't run fifty meters without falling. Ios's new body is a terror, feared by all and constantly suspended from school. While the angel and devil have primary control over the bodies of the twins, reflex actions and memories of the other souls (still alive within the bodies) do appear. More importantly, the human bodies cannot handle the powers that Sword and Ios had used with ease. This a problem especially for Sword who is both over eager to use his powers and targeted by devils and angels. Taken from doushi-sumeragi.net

Kazuhiko is a black ops agent who is called on an unusual mission: he must escort Sue, an innocent waif who has lived in isolation for years, to an unknown destination. But there is a dark reason for Sue´s life of captivity, and Kazuhiko discovers that his mission is more dangerous than it looks.

From Intercross:

1. Bokura no Himitsu o Kyouyuu Shiyou ka
Yuka goes to Ikimonogakari's room to ask them to solve her love problem, but unfortunately, they couldn't help her. To make her feel better, the people in the club gives her a piece of candy. Yuka eats it, and she suddenly gets cat ears and a tail! What happened to her? Will she ever go back to normal?

[T/N: Ikimonogakari literally means "(person) in charge of living beings"]

2. Colorful Shounen to Monochrome na Atashi
Naoki and Kiyo have known each other for a long time because they live in the same apartment complex. One Valentine's Day, Kiyo gave Naoki a chocolate cake, but Naoki threw it away and laughed it off. Because of that, Kiyo doesn't make sweets anymore! Because Naoki's dad is Kiyo's dad's boss and they are going on a trip, Kiyo has to make food for Naoki. Will Kiyo re-live the trauma of the past?
(Also included in the Sweets Fortune Telling Anthology as Boy of Macaroon story)

3. Kaibutsu-kun ni Rei
At the Christmas training camp, Yuzuki was paired up with no other than... that guy?!

4. Itoshi no Himeko-chan
Anri, who is usually bad at handling boys, is asked out by the school's most attractive guy, Takuma! This is so she can gradually get used to guys, however, does Takuma have another agenda in play? What is going to happen between the two?

5) Shiro no Kiseki

About a boy of thirteen years who always tries to be a hero and for various reasons are involved with monsters, ending in his death, but it revived with the help a little thing (one might say that is the predecessor of innocence) and now must fight the Count ancient.

Daria is a relatively normal girl, despite the fact that she always seems to be the recipient of miracles. But when a strange character appears suddenly, with the intention of keeping his promise to kill her, her average high school life becomes anything but...

Oneshot from Uchuu no Hito

A vampire, a werewolf, and a Frankenstein monster live in a castle apart from humans.

Kai was living a peaceful and secluded life with his special martial arts teacher Gankutsuo, until the day he rescued a beautiful girl, Lee Shuurei, who was tumbling down a waterfall. He has no idea what she means when she asks about a "Tenraimon", but Kai is soon drawn into her problems when her pursuers arrive. Meeting her will change the course of Kai's life!

A shape-shifter wolf who was once a human, but became a demi-immortal when his lover betrayed and murdered him, adopted an orphaned boy, who is now a young man. They travel together, exorcising evil spirits and demons. Trouble follows and finds them often, but they always manage to come out on the other side, pretty much intact.

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 Tokyopop:

Fujiwara Sunao is a rather unusual young lady. Not only does she prefer to wear her hair short and dress like a boy, but she also possesses the power to control water! One might think Fujiwara would be an odd fit at her school, but strangely, she's not. Between the destructive and demented school president, the kooky and somewhat stalker-like school nurse, and the obsessed underclassman who wants to be her apprentice, Fujiwara may be the sanest person at the school--which is a big help considering she may be asked to save it!