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...?

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 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...?

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.

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?

One day, Nao's father suddenly announces shocking news! Because his friend helped him with his debts, Nao's father agreed to have Nao and his friend's son engaged! Nao is furious with this agreement and transfers to her fiancé's school, Kaei Academy, in order to make her fiancé break off the engagement. But how can Nao force her fiancé to break it off when she doesn't know what he looks like?! Join Nao in her quest to find her "husband-to-be"!!

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...?

Alicia Faitlin, daughter of an impoverished aristocratic family, was forced into an arranged marriage by her uncle, but the groom is killed suddenly in the middle of the ceremony.

Although Alicia has been labeled “The Princess of Death” due to this incident, there's someone pursuing the matter of a second marriage with her. He is an upstart noble whose family was recently promoted to the ranks of the aristocracy, Kashburn Licen. This man is rumored to be a "Tyrant" but-?

Yuina can't figure out why her boyfriend keeps avoiding her.

Student Council President Yuushiro Seiji launches an investigation into a string of serial arson at Sakuragazaka High School. His only lead is the schools most fearsome delinquent Kazunagi Soyono, who was present at each incident. But, when Soyono discovers Seiji's dark secret he's forced into a dire position. Either clear Soyono's name or lose his position as President. The problem is that Soyono may not be as innocent as she claims to be...

From Transcendence:
Tong Danwei is a high school freshman with romantic dreams about the boy she is fated to meet. While on the way home from picking up groceries, she runs into a pretty boy, and that’s where our story begins. Will she find love in high school? And more importantly, will any boy be able to overlook the fact that although she is in high school, she still looks like an elementary student?? Follow along on Tong Danwei’s adventure of love and high school angst, with plenty of comedy thrown in to the mix.

From Girls' Generation Scanlations:

Almost a year has passed since Tokio-sempai unexpectedly told Yousuke, a student and lover of plants, "I fell in love with you at first sight!" So every day, Yousuke is continually on the receiving end of Tokio’s relentless attacks. The handsome Tokio, who is also a good student and successful with girls, harasses Yousuke daily, pushing him farther and farther away... or maybe...

Also contains the short story Kamisama wo Yameru Toki (c.4).

The official Ore no Imouto ga Konna ni Kawaii Wake ga Nai Anthology Comic.> Spin-off of Ore no Imouto ga Konna ni Kawaii Wake ga Nai( http://mangapark.com/search?q=ore-no-imouto-ga-konna-ni-kawaii-wake-ga-nai )

From Shoujo Crusade & Chibi Manga:
Anzu currently works part-time at a beach house however when it comes to serving male customers, she can't help but be cold and shy. When she accidentally spills a drink on one of them, a male co-worker saves her who ends up being her childhood friend Rei. Anzu is happy to reconnect with Rei, however, Rei might be after a bit more...?

When Hina hits a homerun ball and goes to get it back, she realizes she has damaged a shrine with the baseball. When she touches the object inside the shrine, the object is absorbed into her, and she becomes the shrine's god. Now she is protected by the shrine's guard dogs, Shishi and Koma. On her journey she meets other spirits, guardians, and the legendary nine-tailed fox.