From Winter Translations:

This is a story about a pair of twins who're, undeniably very different from one another. Big brother Shuuya and little brother Yuuta are basically light and shadow...

From Loveless' Site:

Amidst the crowds in Asakusa district, Tokyo, a young man is assaulted by a group of bandits. When a red-haired stranger comes to his rescue, Suoh falls in love at first sight, but all's fair in love and war.

Touge Yuugiri is a chick magnet. Without lifting a finger, girls vie for his attention, "accidentally" topple on him, or even invite him to spend some special time alone—it's almost as if he is the protagonist of a harem manga! But Touge could not care less about the attention, as he is gay and feels nothing towards the opposite gender's affection. Yet all his attempts to escape, reject, or scare them away have the complete opposite effect, only intensifying the girls' admiration—as if some cosmic interference was at work. Bombarded by nonsensically perverted situations and unwanted sentiments, Touge's life spirals into a living hell, truly reflecting how one man's dream can be another's nightmare.

*The series alternates between different sets of pairs. Although it's supposed to be read as a whole, you can skip volumes with the pair(s) you don't like. Warui _____ Featuring the school delinquent Towa Aikawa and the student council president Mikado Shirahane. (Pair 1) V. involving this pairing are: V.01, V.02, V.04, V.07, V.11 _____ ja Nai Kedo Featuring Shuuji Yukimura, the formidable student council vice-president, and the problematic childhood friend, Ryuuichi Shinonome (Towa's friend). (Pair 2) V. involving this pairing are: V.03, V.05, V.08, V.10, V.? (The love troubles continue for Yukimura Shuuji and Shinonome Ryuuichi as obstacles arise between them under the guise of Kousaka Nao, Shinonome's friend. Can they finally reach an understanding and solve their miscommunication?) Mujihi na _____ Featuring Nanao Shirahane (Mikado's older brother), a male siren, and Kuon Aikawa (Towa's older brother), a fellow student attending the same university. (Pair 3) V. involving this pairing are: V.06, V.09, V.12 Shouwaru Ookami ga Koi o Shita Rashii (Wicked Wolf Seems to Be in Love) Featuring former student council president, Shirou Akagi (Mikado's rival in Warui Koibito and Warui Oujii) and disciplinary committee member, Nao Kousaka (Yukimura's rival in Sunao ja Nai Kedo). How will those two damaged people find their respective love? (Pair 4) V. involving this pairing are: V.13

Tsuji Motochika is a guy who loves little girls. Yuna looks like a little girl, but she's actually older than Tsuji. Also, she likes much older men.

Together, they make an agreement to show each other's greatest desires - Tsuji's father and Yuna's little sister - and in the process, learn that age is only a number.

Someone is trying to kill Maejima, the unassuming Archery club adviser and Math teacher at Seika Women's High School. What appears to be pure, dumb luck has gotten him through several attempts unscathed, but he has no clue as to the perpetrator and the Principal would rather not involve the police in what's "surely just a student acting out". With the entire faculty and student body as his suspects, Maejima struggles to discover the culprit before his luck runs out.

Maya is a mysterious young girl who is hired as an assistant to detective Matsunomiya. The Imperial City of the Taisho Era has a mixture of Eastern and Western cultures... What kind of adventure will the two encounter here?

Spin off of Hitsugi no Chaika. Takes place in high school.

It's the typical setting of a J-RPG. be a hero, find companion, defeat demon king, go home, have a party. The end, good ending, roll the credits. But that's not all...

What if i told you, that after all that credit scene, and all the character just froze up as the "game over" sign comes up, there's a character who suddenly regain his consciousness?

What if that there's not just one, but the entire hero's party suddenly regain consciousness while the other NPC just stood there like a display ragdoll?

What if i told you, that this whole hero defeats maou fiasco are but a plan devised by the great demon king himself to teach those hero about despair?

This is a story about a heroic companion who is loyal to their friend
This is a story about a heroic party who was cursed by the so called demon king.
This is a story about despair
Tthis, is the aftermath of the Final Quest
This, is the Final re:Quest

The story begins in the near future, where a social mobile network called the "Kizuna-Topia" (Bonds-Topia) controls all communication and surveillance in the wall-bound city.
In this city, two sisters, Enna and Yayako, come face to face with the ongoing man-hunt for young, healthy children. The kidnappers take these kids to the white tower to extract their brains and sell their bodies. This man-hunt, led by the local police known as the "Jikei," is counteracted by the mysterious being only known as "The Witch." Enna, Yayako, and other residents of this city are trapped between the ongoing conflict between the Jikei and The Witch.

From Tokyopop:
Rey Yan was an orphan with no home, no skills, and no purpose. But when he comes upon the PaSa sword, a cursed blade made from the bones of the demon king, he suddenly finds himself with the power to be a great hero. The sword's creator is the evil Shiyan, the royal vizier who needs the sword to assist him in releasing his ancestor, the demon king.

Biohazard 3: Last Escape is a series of Hong Kong manhua (Chinese-language comics) written as a tie-in to Resident Evil 3: Nemesis. It was published by SkyWalker Comics.

It focuses on a boy named Yamano Koichi, who is one day revealed to be the heir to the supernatural powers of an alien named Babel, who was stranded on Earth 5000 years ago and built the biblical Tower of Babel. Koichi becomes Babel II, armed with supernatural powers and served the Three Servants: the shapeshifting Rodem, the giant, pterodactyl-like Ropross, and the humanoid aquatic robot Poseidon. With his newfound powers, Babel II seeks to put an end to the ambition to Yomi, a man from the Himalayas who seeks world domination.

The story starts with the death of Hikaru Mikado. That guy was a natural charmer, a “harem king”, but had no real male friends. After he died, he became a ghost, a soul, but Koremitsu Akagi can see him. Koremitsu though, isn’t really like Hikaru. His red hair and his evil-looking eyes make him look as a delinquent, even though he is very kind inside. Hikaru asks him a favour: he wants to fulfill a promise, which he couldn't fulfill anymore. The promise was to give his girlfriend and fiancée, Aoi Saotome, seven gifts for her seventeenth birthday. Koremitsu accepts, and has to work hard to help fulfill Hikaru’s promise with Aoi.

In a certain village, in a certain cave, lies a young girl that has been sacrificed. A certain mysterious man comes to her rescue...

Another series based in the original world of Yurara no Tsuki.

In the rural and peaceful Belzenia-Asmodin Empire, women of all ranks, ages, and marital statuses have begun disappearing one after the other. All they have in common is that they are both beautiful and reputable. Where have the stolen women disappeared to - and who will be targeted next?

Future-Retro Hero Story is set in the same universe as Outlaw Star--in fact, it is the origins of the Towards Stars setting. A pulp science-fiction series with plenty of humor, action, and adventure to go around, it's the story of Juji Godoh and the ship he inherits from his grandfather, Captain Roger Fortune!

A guy named Yuuto (an otaku) is interested in a web artist known as "Sayane." Recently a girl at school named Kashiwagi Kotone over-heard a conversation about Yuuto liking the web art of Sayane; but it turns out that Sayane is Kashiwagi!?! Yuuto hasn't figured that out yet... but he got a job at his favorite anime shop and caught Kashiwagi in that anime shop...

Mi Ju, the most beautiful cosmetic model of CF, and her school friend Yu Jin, are thrown to the past where at that time people's opinion about beautiful woman are different from nowadays. Mi Ju who is loved by her beauty and body height, in those times was considered as 'ugly woman'. They must find ways to get back to the future if they don't want to live in those times forever.