A girlfriend decids to dress up her very effeminate boyfriend in a Yukata, but he takes it personal and accuses her of loving females only, and escapes to the fire work festival. Its a trap oneshot, gender bender fun, and the same author of The Night of the School Trip oneshot.

From Solaris:
After spending half a year abroad, Kinosaki Yuichiro is in for a shocking homecoming when he discovers that his inventor/scientist father has given his 3 dogs the appearance and abilities of girls. Now he is in for a ton of grief as he tries to cope with these changes.

The official Infinite Stratos Anthology comics.

[From AnimeWaves]:

Saruno runs a bodyguard service company with his assistant, but they hardly have any jobs. One day, a fateful encounter with a girl called Meruo started a whole series of interesting adventures.

Fuuma Kotaro, a ninja, is a Kagemusha (body double) for Houjou Ageha, a princess. He masquerades as her when they go to school.

High school student Akira Harisugawa has been in love with Mao Satomi, a girl in his grade, ever since grade school. The only problem? They've been best friends ever since Akira saved her from being hit by a car, and he doesn't want to ruin their friendship! That is until one day, when he finds a mysterious mirror...

Natsuo recently got a hot private tutor for his upcoming entrance exams. But there's something funny about Miss Hibiya that he just can't put his finger on. Miss Hibiya helps Natsuo on both his exam and his love life at school.

From ADV Manga:

The prestigious Aoi Academy caters to an elite collection of young magic users. But 17-year-old Kazuki Shikimori is a student who passes muster in name alone. He is the youngest in a long line of sorcerers, but the family's long-running talent for the black arts ended with this average student. That doesn't stop the female population of Aoi Academy from vying for his attention, though! His impeccable DNA will start a teenage war of lovesick girls!

Some Horizon 4koma from Animedia> Spin-off of Kyoukai Senjou no Horizon(http://www.mangawolf.com/search?q=kyoukai-senjou-no-horizon)

Twenty-four-year-old Kirara is on her way to her wedding when she is killed in a car accident. However her love for her fiancé is so strong that she is permitted to return to earth as a ghost to see him. But she is sent back 8 years in time, to when she and her fiancé first met. However her own meddling in the past may make her 16 year-old-self turn away from her would-be fiancé.

Volume 1: Kouichi and Mao are childhood friends, but as they enter High School, they become more and more distant. And as Mao becomes more popular and beautiful, Kouichi wishes he could be popular too, and eventually get a girlfriend. Mao decides to help him... (Written by Aymie) Based on a bishoujo game. As per the title, "Various Heroines", each volume of this manga focuses on a different girl Kouichi can eventually end up with when you play the game. So, think of each volume as a story separate from the rest.

Photography is the art to grasp beauty with the one and only tool, a camera. Ooji's dream is to become a photographer that photographs at the front lines of war, to take pictures of historical events taking place in front of his eyes. However, his childhood friend, Sumire, doesn't think that he is capable of becoming one.

In his photography club, Ooji shows his photos to the group, and his upperclassman, Ran, points out that Sumire is a good target to photograph. Ooji manages to get permission to take photos of Sumire, and during his shoot, Sumire notices that Ooji is acting differently than before. Later they find out that one of Ooji's pictures won an award! Sumire congratulates him, but Ooji sees beyond his award. He claims that he learned that he has much more potential than he thinks. Ran, overseeing this, plans to take Ooji to the next level so he can capture true beauty through the lens of a camera!

Kouta and Kirishima Honoka are friends and really close. Actually Kouta is in love with Honoka but he doesn't have the courage to tell her. One day after returning from school he found a naked girl in his house lying in a doll box... She happened to be LALA, a prototype android sent by the ministry of welfare as a love assistant due to the decreasing rate of couples.

Haruka and Kanata's cousin Yuzu is coming to live with them, but she hates men. Enter Haruka's brilliant idea: Kanata should crossdress.

A collection of three separate stories.

I. Sui-Ren is Here.

II. Alice in Cyberland.

III. Mother's Guardian.

Oneshot:

There is a saying that if you find a Japanese maple leaf with eight tips you will find everlasting love. A popular high school actress is now making a film about that legend at the main character's high school, who in turn has a crush on her. One day after school he runs into her and helps her escape from some pursuing staff members. It turns out that since she started acting right after middle school she hasn't had any experience with love and that is hurting the production of the movie. So to get some experience with love she invites him out on a date.

Included the following stories:

Volume 1: Koisome Momiji (Pilot)

Volume 2: FamiDol!
Daichi's, a teenage boy with little experience with women, life takes an unexpected turn of events.
After his mother's remarriage, he obtains a new sister, who is no other than the famous idol Asano Nanami.
What is Daichi going to do when they end up alone together and Nanami wants nothing to do with him?

Mei no Naisho revolves around the life of the title character Mei Haruna, an effeminate young boy who was raised by his witch mother as a girl, and always thought of himself as female. His mother was the only family he had, so after she died, he transfers to an all-girls high school and resides in the school's dormitory with his familiar Abel, who is talking cat, and his roommate Fuuka Honjou, who is a member of the public morals committee.

Shortly after arriving at the school, his new friends discover after a magical display in the dormitory community bath that he is actually male, though this comes as quite a shock to him despite him being aware of the physical differences between him and normal girls. Despite him being found out, and after some helpful intervening of the perverted student council president, the principal of the school decides that he can stay at the school.

The next day, Mei comes to school with Fuuka and apologizes for hiding the fact that he was a witch, and informs the others how he is apparently male. The other students quickly accept him as one of their own, and are impressed how he can use magic.

Set three months after the first series.

A young boy is saved by a mysterious gunfighter who uses magical bullets. She is the greatest magician in the world but disappears shortly after saving him. Having fallen in love with her, he trains to become a gun fighter and ten years later, his search comes to an end but his adventure has just begun. Kurohime is a buxom witch with the power to control magical guns. She once made the mistake of challenging the gods and was cursed for her foolishness! Transformed into a little girl named Himeko, she can only regain her former body and powers when she falls in love. But finding love in a world fraught with evil is no easy task.

From VIZ:

Seiji Sawamura is the toughest seventeen-year-old in town, feared by all for his fighting prowess and his deadly "devil's right hand." But at heart, Seiji is a softy, and all he wants is an end to his seventeen-year history of being a lonely single guy. Unfortunately his tough-guy reputation only serves to decrease his popularity with the ladies. But what happens when one day, his right hand becomes a girl?!