All Arisa wanted was to go overseas for the summer, but instead she found herself roped into an Omiai with the heir to the Narimiya Corporation. She doesn’t want to be involved in this and is trying to find a way out, but Narimiya has decided that he wants to marry her – and actually has the romantic skills and determination to win her heart!

-- Onigiri Gakuen

Chapter 7 - A girl becomes the comfort sex friend to a playboy that she secretly likes and hopes that one day he will see that she's all he really needs.

It is the year 1999. In Nagano Matsushiro stands the pyramid of Japan, the private Voltstein Academy.

This place is famous for repeated occurrences of occult phenomena within its premises. Hence, it is also called the Occult Academy. The dean is committed to studying the occult, while the students are zealous in their everyday schoolwork.

One day, the dean passes away and his occult-hating daughter, Kumashiro Maya, visits the academy. There, she meets a self-proclaimed spoon-bending "time agent" from the year 2012, Uchida Fumiaki. As the two encounter various bizarre phenomena within the academy, the reason for Fumiaki's timeslip to 1999 becomes clear.

From Aka Roze Tenshi

Story 1 - Let’s Akuma Tech Kyoushitsu :
Minami has been rejected by her crush for the tenth time after confessing her feeling ten times. While being depressed in the library, she caught the attention of the school idol Ichinose Kouki. Smart and with good looks, Ichinose’s popularity is known all over the school and girls flocks around him. Minami end up learning ‘love tech’ from him to get to her crush and the ‘akuma love tech classroom’ begin…

Story 2 - Kimi no Soba ni Wasuremono

Story 3 - Sensei data hazu na no ni

Story 4 - Nise Love

Story 5 - Satou-san Renai Kakumei

From Manga Abyss:

Having just transferred to a rural school, somehow he got engaged. Also, he suddenly attacked a girl at a rural ceremony....?!

A collection of short stories by Tomoko Hayakawa.

From Viz:

Shurei Hong, destitute but of noble birth, has always dreamed of working as a civil servant in the imperial court of Saiunkoku, but women are barred from holding office. The emperor Ryuki, however, refuses to take command, leaving everything to his advisors. Shurei is asked to become a consort to the emperor to persuade the ne’er-do-well ruler to govern.

Shurei enters the palace as Ryuki’s consort, but he has yet to seek her out. It is rumored that men, not women, share the emperor’s bedchamber. Shurei must think of a way to stop the emperor from shirking his responsibilities, but she has to find him first!

The story is about how and why a guy goes from a worker at a dead-end job to becoming a boxer.

From DrMaster:

All he ever hoped for was to be one step closer to becoming a priest, but Masato Kamioda gets more than he bargained for when he suddenly finds himself as the only male student in a pilot program at an all-girls divinity school.

Consists of 4 oneshots:

3) Devil's Baby-Sitter
Nao is saved by Shouji from a group of delinquents. However, Shouji himself is a delinquent and makes Nao his slave. But after a fight in which Shouji was hit in the head, he reverted back to his 7 year old self?!

From Chuu Chuu Train:

My class’s boys made some sort of group called O.P.D. (Mew Mew Group) and that stupid idiot “Shou”. Why do I always care about him? Why does he make my heart beat so fast? This sort of emotion is definitely not friendship… probably very special… Then that means I like–?!

From Aerandria Scans:

Kanako is an unattractive and not very capable office lady, until the day her mother passes away and she turns out to be the sole heiress of the old and elite Kinaga house. So suddenly, Kanako has not only to uphold her duties as an heiress, but to turn into an attractive lady so that she can marry accordingly to her new status. Thanks to the family butler and her own efforts, she manages somehow, but even in the middle of her newfound glamor, her world still continues to revolve around her butler...

From Aerandria Scans:
Arima and his little sister Chihiro are the twins of the Momoyama family. Six years ago, they've overheard their parents say "We will tell them the truth when they turn 16." The two worried that they might be adopted during those six years, but the truth they learn on their 16th birthday is even more shocking! Also includes an award-winning one-shot.

From Yen Press:

Welcome to the prestigious Saint Leaf School, where, among other things, the boys are so pretty they give the girls a run for their money! Amidst this bed of flowers exists one Hitomi Sakuragawa, a sweet girl with a not-so-little weight problem, who lives in a nearby apartment owned by her doting older brother. Hitomi also happens to have pretty much the best luck on the planet: Her neighbors are some of the hottest guys in school! But will she need to steel her willpower, cut out the cookies, and slim down before they’ll even give her the time of day? Or will they be charmed by her kindhearted, genuine personality? It won’t be long before Hitomi discovers that the road to a healthy lifestyle is paved with hilarity!

Tachibana Ritsuka is a female second-year high school student who attends Shiko Academy in Shiko Town. She enjoys her school life while living with her mother Maria, but one day, that balance falls into ruin when she discovers several of her attractive male classmate are demons.

A Collection of early stories:

From Covenant of Darkness:

Face, body, and talent, all 3 are what conspires Misako’s love for the star of the basketball club, with a genius ability and super beautiful Urasawa-kun. However, Misako's first and last profession of love in her lifetime was drastically discarded. Strangely, Urusawa-kun decided to model nudely for an art exhibition in hopes to winning a prize because he has an eye for that thing. The lingering affection is banned and the conditions that sends Misako's heart to abide… A romantic comedy treasure?!

From Sura's Place:
Cha Ji-Yyoung is a journalist who makes a terrible mistake and is forced to make amends for his fault. He is forced to crossdress and enter a woman's university to reveal corruptions. His interesting life as a 22-year-old female dancing student begins.

Teppei Arima is a second-year high school student who lost both of his parents in a traffic accident on their way home from a family trip. His grandfather, Isshin Arima, happens to wield the puppet strings in Japan’s vast economy and demands that Teppei becomes his successor as the head of the Arima Group. To prepare for his debut into high society, Teppei enrolls in an elite academy for the scions of the rich and powerful.

First Kurumatani Haruko Long series (no more a simple oneshot)!!! By Alessia-chan: Ruki is an otaku and is in love with a character of manga called Shun-sama! Suddenly she meet a guy that will live in her house due to her mother sudden travelling and that looks exactly the same as Shun-sama! But does this guy is really a prince-like such as Ruki expect?

This is the sequel to Violinist of Hameln. So read that first.

This series takes place in a fantasy world with famous composers' music, magic, friendship and dark secrets. Our main character of this story is a young ambitious, energetic boy named Schel. (Scale, as in the musical term) Because of the general of the MagiCorps saved Schel from a Mozoku (Monsters of this world) he has a dream to become the greatest magician ever. So he travels to the capital Sforzando the magic city and enters the MagiCorps School of Magic. There he meets Great, a violin magical music user, who is also the son of the great hero Hamel, who defeated the Demon King Chestra. As Schel tries to become the greatest magician, he also holds some secrets of his own. But how will Schel survive magic school with so many rivals to compete against?

One day, Toto—a 19-year-old virgin, obsessed with girls' breasts—found lying a naked, pretty girl (perfect breasts included), but who was completely without emotions. She learned to call Toto "master" and Toto named her "Kuu."

Kuu has a golem, which protects her from Toto's... advances. It also appears that Kuu has enemies who are after her for some reason.

Will Toto and Kuu make it in this romantic love comedy with a slight mystery? (Perfect breasts included.)