From Nagareboshi Manga:

Mai Kojima is a slightly ditzy sixteen-year-old, but she's gotten her first boyfriend! They've been dating for three months. Even though they should be at their most lovey-dovey, they haven't been able to make out at all… That's because her boyfriend Yu-kun is a super exam-taking student aiming for Tokyo University. Every day is an uneasy one, without much hugging or kissing.

From ShoujoMagic:

Ever since he was small, all the girls in the neighborhood have fawned over Tsutomu Yamaguchi, whose name came from a song and whose adorable face closely resembles the monkey character Monchichi's. Even back then, it was enough to make his friend and neighbor Mikako sick. Now that he's a little more grown, Tsutomu looks like the lead vocalist of Manbou, Ken Nakagawa (Midori friend/boyfriend from Tenshi Nanka Ja Nai; we meet main characters from Tenshi on market/fest), and that makes him even more popular with the ladies. But Mikako--now a trendy teen with modern sensibilities--couldn't care less. Or could she...? Gokinjo Monogatari is a sharp-witted and stylish slice-of-life story!

Continuation (after years) in Paradise Kiss.

From K.I.S.S.:

Coming to earth to live the high-school life he's always dreamt of, Hirito finds himself in a bathroom on top of a naked girl! It turns out she goes to the world renowned Konoeghara Academy. Hirito is shocked to find the school only consists of seven students in total! Why in the world does the one of the most prestigious academies in the nation only consist of seven pupils...?

Full-color one-shot about girls with guns.

From Nagareboshi Manga:

There's a jinx at Haruru's school - if a couple sees the blue train at 6 am together, they'll be together forever! But if a couple sees the blue train at 10 pm together, they'll break up!
Haruru is going out with Nagi, a boy who goes to another school, and their love is just starting to blossom. But what happens when Haruru happens to see the 6 am blue train with someone else?!

From DMP:

Haruka Iijima and his teacher, Nakagami Sensei, are in the middle of a bitter-sweet relationship. Being a student and teacher couple isn't easy, but they're about to find out that's the least of their troubles. Nakagami Sensei's family, the gang of impossibly beautiful, age-defying Nakagami Sensei obsessed individuals might just turn out to be the worst nightmare. Will this love be able to survive the perverted mystery that is the Nakagami Clan?!

In the series:

V.1 - Nakagamike no Ichizoku

V.2 - Akuma Kiru

V.3 - Kamenbutoukai de Aimaseu

Included oneshot:
Kuroneko to Waltz (Waltz with a Black Cat)
Hirose is mad. Once again his boyfriend Matsui has cheated on him, with the sorry excuse of: "Sometimes I wanna see a girl's boobs more than a guy's d*ck."
Crying at a nearby shrine, Hirose curses Matsui... And the next day, outside Matsui's apartment, he finds a black cat with a scar just like Matsui! And Matsui seems to have disappeared...

From ShoujoMagic:

Story 1: Automatic Angel
Serika, a high-school student, is known for being a well rounded girl with an attractive face and figure. She is clear-headed and has a talent for sports. But she's an... android!?

Oneshot: The Winter Was Trying to End
Tale of a high school professor and student.

Gorou has a crush on his older stepsister Haru. Unfortunately for Gorou, Haru happens to love teasing him sadistically in every way possible.
A 4-koma comedy about their wacky day to day life and interactions.

Hoozuki-san Chi no Aneki - Nano Shucchouban and 2 chapters of Hoozuki-san Chi no Aneki - Nano Branch are included in volume 3.

Much to her embarrassement, the shy Mashio-chan wins a set of couple tickets for the amusement park. She feels at a loss for what to do since she has always been bad with men. So what will happen to her when the drama club president Katokura Aki suddenly declares that he would erase her awareness...?

Prequel about Nishizumi Miho: her first meetings with her friends in elementary school and how she came to start avoiding tanks.

Hinako is in her second year of junior high. In her third trimester, she has to move to a big city because of her father's work, and she has misgivings about fitting in... But that's not the worst of it! -- The school she transfers into used to be an all-boys school, so now there are only two girls in her class including her!?

Misaki Aguri is the only girl in the Judo team, and she has a crush on the Captain. One day one of her friends tells her of an old Chinese magic. That if the wears the same pajamas as her crush, that she will appear in his room! Just slide his picture under your pillow and TADA! However, things don't go exactly as planned...

This was Yuu Watase's debut piece.

Follows the adventures of a scientist Haiji and his assistant Chitose. One day the doctor is called to resolve a mystery about a glowing corpse. From the will of an unknown power the corpse then transforms into a monster and Haiji has to defeat it, to learn all about a mysterious black apple which can regenerate itself and which when eaten will enable someone to control gravity...

Winner of 2011 Golden Future Cup. (Oneshot)

From Yen Press:
Michiru Kita’s a weak-spirited girl who has a hard time saying what’s on her mind. One day, she notices mysterious, ring-like markings around the necks of two of her classmates, Chika Akatsuki and Shito Tachibana — two boys who miraculously survived a horrible accident six months before. Michiru, possessing the rare ability to see these rings, knows that they warn of impending death. Thinking that, perhaps, she can do something to save her classmates’ lives, she approaches them…but it seems the boys have already made a different kind of deal and garnered themselves a heavy debt.

The male lead has gynophobia (fear of woman) due to a traumatic experience. Following the recommendation of his sister, who is a nun with little brother-complex, he enters a previously all female school that now has a 9:1 female to male ratio. Then the queen of the school demands that he work for her as her secretary! How will the gynophobic guy cope working so close to the queen?

A samurai manga about a boy named Zan. Zan's father was a legendary swordsman who used a sword which had no blade (think Sakabatou from Ruroken). Zan's father died one day, and ever since, Zan has wanted to follow in his fathers footsteps.

The manga starts off with Zan being transfered to a new high school in his second year. When pushed, Zan somehow becomes super strong and has incredible sword technique that allows him to beat his enemies.

From etc:

Eiko is something of a plain Jane and a doormat, while her best friend Moe is a head-turning beauty. Despite their differences, their friendship is as strong as ever.
Guys are always asking Moe out, but her answer is invariably "Only if you promise to put Eiko before me."

From Shoujo Sense:

The packed morning train isn't a good place to be if you're small; a fact that high schooler An knows all too well. So when a boy rescues her from the crowd one morning, she should be grateful... right? The only problem is, he treats her like a little kid! Who is her rescuer, and what will happen when she meets him again...?

"I want to get it on with my cute girlfriend!! But whenever the time is right, a ghost gets in my way?!"

Shuusei has a dream of his friend, Hinata, wearing a maid's uniform. When they next meet, Shuusei reacts strangely, and Hinata eventually confronts him. Explaining his behavior, Shuusei is asked to meet Hinata at his home, where he'll soon understand...