A cynical romance, 'Have you been addicted to love?'

From MangaHelpers:
Before they enter high school, the boys Meguru and Shou are whining about the fact that neither of them has a girlfriend. A strange, large-breasted woman shows up, claiming that she will fix their problem, and kisses Meguru. This odd occurrence is pushed out of the boys' minds when they meet up with Souko, a friend from elementary school, who is going to be in their high school. She's grown up into a pretty young girl, and it seems like the boys might have a shot with her!
That evening, Meguru realizes that the strange kiss may have had more meaning than he thought: he's turned into a girl! He convinces Shou and his mother of his identity, but no one has any idea how to turn him back. Now he's going to have to learn how to be a girl and let go of his hope of dating his cute childhood friend Souko. What will happen to his hopes for a popular high-school life?

A story about a demon hunter named Rano who is trying to find his sister. Along the way he finds a person who has the same teeth structures as demons yet is not affected by sunlight. This person, Lessa, seems to remember who Rano is, but Rano does not remember who he is. Rano only dreams of this person; what are the connections between these two?

Rinne, a huge fan of Buddhism, was searching for a "monk-type," a boy as calm, intelligent and diligent as Lord Buddha himself, when she set her sights on a young, handsome monk-in-training, Yuuryou. She soon learns that this kid, out of his robes, is not her dream boy, but a shallow, irresponsible lady killer who goes by Yura. Is Rinne going to give up on her fantasy, or is there more to Yura than meets the eye?

For fighting and humour fans Jo Pae, a not really sane boy, in our modern days, he wants to become emperor of Korea... His first step when he enters high school is to become the leader of the strongest school there is. No one expecting it, he actually takes down all of the school's yankees. Jo Pae is now the enemy to kill! All rival schools wants his head whatever the means!

From Shoujo Crusade:

1-3) Lovers in Conflict
Because of her sister who suddenly ran away, Sagiri ends up getting married in her place. Her husband is hard to understand and is a bit of an S. What will happen to their married life?!

4) Wild Rose's Crown

Imagine a senpai you don't get along with. Then imagine having to work with and live in the same apartment as him! With no vacancies in the single's dorm, newbie cop, Kaitou, has no choice but to move in with his senpai from the koban, Himuro. While he's beautiful and excels at his job, Himuro has a mouth on him and he and Kaitou fight like cats and dogs. But then one morning, surprise! A sudden embrace and a kiss!

"Give me back my first kiss!" Romance, trouble and a love triangle. A fiercely tsundere senpai versus a hot-blooded rookie equals a workplace romance!

In the near future, the National Police Agency establishes an elite covert paramilitary division called Minkei or Private Police in English to tackle violent criminals and gangs. Among its operatives include average school student Kou Shirashi and school idol Mikuru Nazume.

Yuria is a humanoid dutch wife (love doll), a female android designed with the sole purpose of being the sex slave of her master. But she has one flaw: she doesn't want to be a dutch wife. After escaping from her creator, she meets Kubo Shunsuke, who gives her a place to stay. Hilarity is bound to ensue as she battles her programming, which draws her towards him and pretty much any other man she comes across.

From DGT:
Yating was working in a recording company until she was fired by her boss (a famous movie actress with a spoiled temperament). Discouraged and jobless, Yating decided to work in a pub where a famous group called "Gangster" regularly played. Along the way, she gets to meet this guy who has the most divine voice. Yating's luck then began to change when her uncle decides to retire and set up his own record company. He asks her to join in his ambition to create the most famous rock group in Taiwan. This is the story of how Yating, being the new manager, tried to create the ultimate rock band!

From Shoujo Crusade:

Takeda Una's ultimate wish is to find a boyfriend with whom to spend a romantic Christmas. All her previous boyfriends were weirdos, so she is nervous about being able to find a normal one. Will she succeed in her quest?

*Also includes another story called Umi ga Kikoeru (I Heard the Ocean).

Sakura is the princess of Clow - and possessor of a mysterious, misunderstood power that promises to change the world. Syaoran is her childhood friend and leader of the archaeological dig that took his father's life. They reside in an alternate reality where whatever you least expect can happen - and does. When Sakura ventures to the dig site to declare her love for Syaoran, a puzzling symbol is uncovered - which triggers a remarkable quest. Now Syaoran embarks upon a desperate journey through other worlds - all in the name of saving Sakura.

Our hero Vash the Stampede disappeared for two years after blasting a crater onto the moon above the desert planet he saved from annihilation. But with good people and bad alike trying to track him down, he won't stay lost for long! Count on more crazy gunslinger action, new dastardly villains...and a new outfit, to boot! Nightow changed publishers to Shonen Gahosha and the series continued to be serialized in Young King Ours magazine. Due to the original publisher retaining the name Trigun, Nightow had to change the title to Trigun MAXIMUM, which isn't a sequel; just a new name for the rest of the same series.

Hikaru finds her little sister Akane irresistible, while Akane sees her big sister as nothing but a worthless pervert. Meanwhile, Hikaru's friend Shinobu, subtly vies for her (Hikaru's) attention while trying to help her deal with her siscon ways.

From Storm in Heaven: Minami has been living with Kuriko's family ever since his parents passed away when he was a child. Over the past fifteen years, things have stayed pretty much the same, but when Minami unintentionally reveals his 'more than friendly' feelings for her, their relationship is changed irrevocably. This is a very funny, sweet story about two life-long friends who fall in love.

A cat went in the hot-tempered KANG Jae-Young's villa.
Forbid approach to my room and my library.
Things must be always in place.
I hate messy things and clamor.
Just follow the rules!
Darn! >v<
I won't be daunted.
It's not like that I want to live passively and say no other words but "meow meow".
Seems to be acting modestly, and all of a sudden extrudes the claws while sounding "Grr.." like a wild cat.
Kya~!
Now can love be formed?!!
Let's wait and see.
The vicissitudinous cohabitation diary~

Side stories of the "Saki" manga in 4-koma format.

Reiroukan is a beautiful house that is currently renting rooms to male and female students. Shirai Genta has just moved to Reiroukan, turning over a new leaf in his life. The house is full of other people with strong personalities, such as the nerdy Tokimaru and the careless and uninhibited Mikoto, who frustrates her friend Midori with her messiness. Genta gets embroiled in all sorts of wacky situations. Soon, though, Genta finds that Reiroukan is scheduled to be closed in a year. At least, there is still a year for Genta to build fond memories with the lively inhabitants of the house!

Second-year culinary student Sakai has always dreamed of opening his own little restaurant and being able to touch people's hearts with his cooking like his grandfather did. Except he's at his limit, fainting in class from overwork and fatigue from commuting three hours every morning just to get to school but there's no way he can afford to live closer.... Until his classmate tells him about an almost too good to believe room share nearby. And so begins the story of four misfit roommates.

Riding high on the memory of a boy named Hikaru with whom she spent a day during her last year of grade school, Megu went through middle school without romance. Now that she's a high school student, she has decided she is finally completely over her first love and can look towards the future. But! Megu meets a pretty girl on her first day of high school who gives her a big hug, and her name is Hikaru?!

Note: this manga is currently on hiatus due to its author's copyright infringement. There has been no notice since June 2012 about its re-appearance.