From Manga Art:
Miyu, whose mom was chosen to be an astronaut, was sent to live with Kanata, a boy she just met. Soon after, Kanata's father leave the two to live alone. Amidst the panic, a mysterious UFO came... and out popped Ruu and his babysitter-pet Wannya. For the sake of Ruu, the four of them start living together......

Every year the flowers bloom. Mysterious Cherry Blossoms blooming all over a crescent shaped island. That island is the island of Hatsune...

The main character who goes to Kazami Academy, Asakura Junichi, has the power to see the dreams of other people in his sleep. He was also taught magic by an old lady that allows him to create sweets.

One day, Junichi seems to have seen someone`s dream again while he was sleeping. Inside that dream, a girl who was a childhood friend of his appeared. But, he was woken up by his sister Asakura Nemu, forcing him to come back to his regular life. Nemu doesn`t actually have any blood relation to Junichi but their bond is deeper than other real brothers and sisters. So deep that it gives the illusion that they`re lovers.

It was another peaceful normal day waking up early in the morning and going to Kazami Academy. Together with childhood friend Amakase Miharu, the academy idol Shirakawa Kotori, the two sisters Mizukoshi Moe and Mako who prefer eating nabe on the school roof for lunch. Going through their day as usual, their childhood friend, Yoshino Sakura, who they thought had moved to America suddenly appears. It was a surprise for Junichi and Nemu. Sakura tells them, "I came to fulfill the promise we made when we were children..."

When he was younger, Kujou Kiyosumi was incredibly awkward and nerdy. One day in elementary school, he courageously confessed his love to a girl, but she told him in front of the whole classroom that he was "disgusting" to be around.

Shocked, Kiyosumi asked the coolest guy in the class, Sagiya Maki, to help him become more likable, too. Thus began the days of training and now in high school, he had finally achieved most popular status alongside Maki. Everything seemed to be going along smoothly until...

Sumi is in love with Mitsuru, but he doesn't seem to be interested in her as a woman. Determined to look more sexy and mature, Sumi takes an experimental growth hormone that her scientist father has been developing. However, the medicine backfires. Instead of changing into a buxom femme fatale, Sumi changes into a beautiful young man! She--he--is so gorgeous and so cool that even Mitsuru begins to take notice. Although the new situation with Mitsuru is imperfect, Sumi discovers that she can be closer to her crush: they can talk man-to-man. Yet, being Mitsuru's friend also has a downside, particularly when he reveals that he is in love with a girl in his grade!

Seung Hun is a handsome playboy who's never experienced true love. Woo Sun is a charming playgirl who wants to be loved for herself and not her beauty.

Jong Yi is the beautiful, mysteriously childlike and vacant boy who becomes the object of their affections. A complex love triangle evolves between these three, further complicated by the involvement of Jong Yi's unfailingly devoted childhood friend and first love, a girl named Yu Ri.

They're all soon to discover that love is a long, painful path...especially if the object of it is completely oblivious to your attentions!

Note: As indicated by the genre tags, there are both shounen-ai and romance pairings in this story. It is not F/M romance only.

From Go! Comi:

When her grandmother passes away, high-school student Kajitsu Toda suddenly finds two hot stepbrothers and an adorable little stepsister dropped in her lap! Kajitsu and her step-siblings have only one thing in common: they were all abandoned by their parents. Against the odds, they've pulled together to form a family without grown-ups. They don't want charity, they don't want pity... they just want their dignity!

Things are particularly tough for Kajitsu and her step-brother Natsu. As kids, they were as close as any true siblings. Now, reunited for the first time in seven years, they've grown as far apart as two people can be. Can they ever become friends again? And can two high school students living together, even as "siblings" ever escape scandal?

Yuuki Ashikaga is a high-school freshman at Sakakino Academy. While working as a student librarian, he grows enamored of Kotonoha Katsura, a girl who frequents the library. Unfortunately, Kotonoha is already dating Makoto Itou, another schoolmate.

The situation is further complicated when Chie, Yuuki's older sister introduces him to Roka Kitsuregawa, her kouhai in the basketball club. Roka becomes interested in Yuuki, who only has eyes for Kotonoha. In order to make him jealous, Roka lies and claims she already has a boyfriend, her former classmate Makoto Itou. Unfortunately for all of them, Roka's lie sets off a chain of events no one could have predicted...

Note: Cross Days takes place in the middle of the original School Days storyline and provides an alternate take on how things might have turned out.

Artist model Nagi has gradually become more and more aware of art student Kaji's meaningful gaze. After working past misunderstandings and miscommunication, the two begin a loving relationship, but even after four months, they haven't moved beyond a simple kiss. Nagi begins to wonder if perhaps Kaji can't accept being with another boy. But Kaji has a secret of his own...

Also contains two oneshots:

• Wish on a Star (chapter 6)
Sei has hated stars since he was little. Will his childhood friend, Daiki, change that?

• Boku no Shôkoi ni Tsuite (chapters 5 and 7)

A former prince and his retinue take Hifumi to a world powered by imagination.

From J-Wiki:
Takashi is reunited with a childhood friend he has not seen in 13 years named Miriko. Miriko, while thought to be missing, became the queen of an alien planet and leader of a strange army corp. To keep a childhood promise, Miriko sets out to take over the world with Takashi. However, Takashi has no desire to do this, so Takashi must stop Miriko's wild behaviors.

From Viz:
A hopeless geek, a beautiful woman, and a fast connection--could the Internet be his ticket onto the express train to romance?
A real-life thread on an Internet forum sparks a nationwide phenomenon! A nerdy otaku meets a girl on a train and posts an urgent query on the Web--How the heck do you talk to girls? What should he wear on their date? Where should they go? The forum's response was overwhelming, and the thread continued to grow along with their relationship.

Collection of crazy tales of love. 1) Electrical Shock Love Machine One of the most beautiful and popular girls in school, has zero interest in boys or romance. That is, until she meets Bansaku. He seems like a very average boy, unless one looks very closely... and Madoka does. She becomes so hypnotized by the little things about him that she loses her good senses, and when she regains them, she finds herself touching poor Bansaku, who has no idea what she's playing it! Madoka has spent her life dodging the unwelcome advances of desperate male love machines... Does Bansaku feel the same sort of disgust for Madoka's long-repressed, electrically-charged lust? 2) My Baby: Morimura Aki's handsome looks attract women by the thousands, but his violent manner keeps them all at arm's length. As an innocent bystander, Moe couldn't have cared less... until one of his outbursts led to her injury! Now revenge is a matter of pride. But when she exacts it, there's an unexpected result...? (No, really, you'll never guess if you don't read it!) 3) Like in Cinderella: When Chiyo lost her job and had to take on work picking weeds for the rich, she never expected to become like Cinderella. But when Yoshimune, the handsome young master of the Tokugawa Financial Empire, runs away from his "castle" with her, that's what Chiyo is certain will happen. But there's no guarantee that these two will live happily ever after, because this fairy tale isn't Cinderella's -- it's Chiyo's! 4) Don't Get Me into It: None of Ichirou's home tutors ever come back after the first tutoring session, but Takigawa Megu can't imagine why -- he's so cute! And... tied down in his chair!? It turns out that Ichirou is a complete and utter brat! Megu makes it her mission to prove herself superior to him, and Ichirou is actually impressed? Now, every time he gives her an inch, he gets her a little more into it. Before long, Megu feels like tutoring Ichirou... in the ways of LOVE!

From Forever More:

Kazuha, a naïve boy from the countryside dreamed about working under Hongou, who manages a restaurant in Tokyo. After cheerfully arriving in Tokyo, what awaits is a person who is totally different from the Hongou he admires. He never hides his temper and is a super selfish guy! While disregarding Kazuha's uneasiness, Hongo made Kazuha live with him?!

From Attractive Fascinante:

Miyashita sensei was always an overachiever, but his perfect life was disrupted when he met his desired-filled student, Jindou. Trying his best to keep Jindou back on track, sensei had to guide Jindou personally as well as to fend off his ex-partners. Love developed as time went by, but sensei kept a distance from Jindou by trying his best to maintain an innocent relationship between them. Would Jindou succeed in breaking down sensei’s territory?

Moka's brother Megu is returning from New York City where he lived with their father. Not only that but she is also interested in the subject of art. When she goes to the library she meets Masato-kun, whom she begins to like. But Masato-kun turns out to be a playboy. Will Moka's determination win him over?

From Dan of Population GO:

Three friends, Kotori, Yuuto, and Rin are trapped in school when the principal halfheartedly summons a horde of demons. The demons make a pact with each student in exchange for possessing them. Most of the students wished to be be good looking or to have longer legs, but Yuuto manages to stave off the possessed student body while Rin overpowers the weak demon possessing her. Yuuto makes a pact with a demon to return the school to normal, but what will happen to the school now that each student is being possessed by a demon?

4-koma Based on a Novel - Date A Live.

Because of an unaccepted mariage, Norika has only had his parents for family. Unfortunately after his mother had passed away, he had to grow up on his own and to take care of his ill father.
Yet, after 15 years of silence, here comes the brother of his mother asking Norika to come and sign in a school located on an island while he would be staying with his father.

But the drawback of this school is that it is divided into two parts : wealthy people and not wealthy people. Hence the strong rivalry that has been born and ruled by the president of the students : Norika's cousin, Yuusuke.

From MangaProject:
Imagine what it is like to be raised by a gay father who insists that you call him "mom". The main character turns out to be a woman who doubts her sexual orientation, until she meets the right guy. She is so sure that he is "the one," that she goes out of her way to pursue him and then marries him lightning fast! Essentially, the rest of the story is about keeping the chemistry (a little twisted and crazy though).