From Viz:
Mimori Kosaka's dream comes true when she's accepted to the Meidai Attached High School and gets to wear their super-fashionable uniform! She's excited about having a fun freshman year of high school, but things don't turn out as effortlessly as she had hoped.

Includes the following side stories:
Volume 1: Basically Pure-Hearted
Volume 2: Kiss the Mike!

From today, Meguru Kinosaki is a freshman in highschool. But it's not only that she hasn't had a first love yet; she's in fact a clean girl who's never been in touch with any guy apart from her older brother Toshiya. With this pure Meguru, her classmate Yuuma falls in love at first sight. He starts a determined attack, but the over-protective big brother blocks his way! Now Meguru's days start to turn around between a big brother with a sister complex and a pushy boy...!?

Kyoko Suomi is the princess of Earth in the 30th century. Kyoko goes to school among the commoners, unwilling to reveal her true identity and ascend the throne. The king will allow Kyoko to live as she pleases if she can revive her twin sister Ui, who has been trapped in time since birth.

From Shinnen:

The Hachiouji family hunts demons in the darkness. The heiress of the Hachiouji family, Takamichi, lost her older brother at a very young age. She isolates herself, but, one evening, two werewolf pups are given to her. After just a few years, they have grown quickly, and they even go to the same senior high school that she does!

Ichigo is out on a date with her crush when suddenly she's involved in an odd incident in which her DNA is merged with the DNA of an almost extinct wildcat. When four other girls' DNA is merged with the DNA of four other almost extinct animals, it's apparent that they're part of a much bigger plan. Ichigo and her friends have been chosen to become a part of a secret project called the "Mew Project." Their mission: To protect the planet from aliens who are using the planet's animals to attack humans.

Chica is packed away to sleep in an escape pod in order to avoid a deadly asteroid collision on Earth. When she wakes up, however, she finds herself in the distant future, but still on Earth. Earth is now filled with strange creatures, like flying fish. She's being cared for in a dome by an android guardian named Roy and a maid android called Silvia. She also encounters a mysterious, friendly man with cat ears, named Oboro. All the future beings are fascinated with her, seeing as she's an 'original' human, but sometimes they forget about the limitations of human lifeforms. Will Chica be able to find a place in this strange new world?

From Chibi Manga:

A story about a sadistic love interest!! A desperate and clumsy high-school girl entered a famous high school in order to be close to her "Prince." Hiroto may be a prince, but he's also a self-conceited arrogant man! Anyhow, Mitsu is still in love with Hiroto. Will Mitsu be able to get Hiroto's heart even though he only thinks of her as a mere “parasite”?

From Sound of Jewels:

She entered in that expensive school because she wanted to meet the prince of this school.
But then she became his target and it looks like this boy is in fact really sadistic! What will she do...?

A calm, quiet life at a new school is just what Aria needed. Unfortunately, it's not what she got! Chosen as Student Council President on her first day, Aria's attempts to just fit in are ruined by her nosy new classmates. Since she can't beat the use of her mocking former nickname, "The Lovemaster" she decides to go with it and turn the Student Council into a dating service! That's great for the school, but will Aria ever solve her own love troubles?

From Shoujo Manga Maniac:
Mimi has given birth to a son, but she won't let motherhood tie her down. She's just as fierce and independent as ever. She's determined to find out what happened to Yuan Qing, her husband and the father of her child. According to the rumors, he was killed in the war, but Mimi knows he's too crafty to let himself get killed.

It's the story of a high-school girl, Hibiki, who falls in love with one of her teachers. The two start dating, but run into a lot of trouble. Hibiki's friends cover for her, and part of the story is also about them.

Also included is a story called Tomodachi Nante Iwanaide in volume one:

A short story about Kumiko's five-year unrequited love to Kanata. Kanata has always seen her as the girl who ate a beef bowl and a good friend. Will that finally change?

From StarryHeaven:

Anjuu Sendou is a nice girl who just started her first year in the Seiryuu Academy Middle School. She is currently living away from home as a boarding student with her pet named Lime. Her father is a sorcerer and her mother is an expert in Chinese kenpo. They are both famous, especially her mother who is called Dragon Momoka.

Because of her mother’s fame, the executive committee wants Anjuu to join the student council. But the council’s president thinks that she is a weak girl, so to prove him wrong she decides to catch the school thief. When things get difficult and she wishes to become stronger, her pet suddenly transforms into a small child with wings (a pre-dragon form, because Lime isn't fully grown) and tells her about her power.

The next time the school thief appears, Anjuu, with the help of Lime, transforms into a new Saint Dragon Girl, defeating the enemies and becoming the school’s protector. Will the student council’s members find out the true identity of the warrior girl? Will Anjuu be able to keep her secret?

A troubled loli witch confides in a kind stranger.

From Viz:

Haruna Aizawa thinks that school life is just like a monkey mountain--all the monkeys form cliques, get into fights, and get back together again. The school that she just transferred to is no exception. There's even a boy called Macharu Yamashita who reminds her of a baby monkey!

From Eclipse Scans:
A school where the students make their own riches. From Models to Computer Geniuses, These students get rich on their own.
Namu goes to a school where all the elite get idolized by the non-elite. Never making it easy to get to school on time, Namu is soon helped by a new transfer student. Who gets categorized as an elite almost immediately?

From Yen Press:

Cute and charming, but not so bright, little Rika is training to become a real wizard. The first step is to find a magic staff. That can’t be too hard, can it? As Rika and Eugen journey deep into the forest in search of this wonderful staff, Rika gets lost encounters the dark sorcerer who kidnapped the princess! Will Rika be able to free the princess and become a real wizard?

High schooler Jenny You is living a dream. In the public eye, she is a delicate princess, a successful pop star, but in real life, she's a rebellious beauty ostracized by her female schoolmates. She and her classmate, Eumpa Won (One), seem to have nothing in common on the surface. Eumpa is a quiet boy, ignorant of the pop culture that has enchanted most of his peers. Having spent his childhood as a depressed prodigy in the United States, he has now resolved to lead a normal life as a regular boy. He likes a cute-but-average-looking girl, Young-ju Chae. Young-ju takes him to a pop concert, and Eumpa is exposed to Jenny's music for the first time. Meanwhile, umpa's resolution to live a normal life is challenged when his music teacher steals the young man's music and attempts to pass it off as his own... So begins the story of One...

From Intercross & Shoujo Crusade:

Chika has always seen Murasame-kun as a rival who manages to constantly piss her off. While wondering out loud to herself, her sister whom overhears Chika, gives her a perfume necklace which supposedly able to capture a guy's heart. The next day, Chika bumps into Murasame-kun and spills all the perfume. As she begins to apologize, he suddenly asks her out?!

From Anime Waves:

Meet Shizuki Maku - to say she looks "above average" would be a slight overstatement, but it's especially bad compared to her older twin brothers, the high-school heartthrobs Retsu and Tetsu. She always wondered whether or not she really belonged in her family, but things take a shocking twist when her brothers plant the suggestion that they may not be related after all.

Now she's supposed to pick one of them to be her boyfriend, all the while defending herself from all the other girls at school who want to keep her "brothers" for themselves! Life isn't easy when you're the ugly duckling!

Sonnan Ja Nee Yo received the Shogakukan Manga Award for shoujo manga in 2006.

From Shoujo Crusade:

Miyako's living her life diligently following rules, just as her deceased father wanted her to. But one day Azuma Koutarou sees her play guitar and blackmail her to join his band. How will she face it up?

There's also three extra stories that are unrelated to the main one.

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?