From MyPersonal-scan/Tcmanga:

A mysterious command arrives from a "King"-----
The life-threatening "Game" has now begun for the 32 students of the first year's B Class.

One day, all of the students in Nobuaki's class received their first message from someone calling themselves the "King", in which was written a baffling command.
That first command was very easy. However, the commands began to escalate until a life-threatening game had begun---

Failing to obey the orders leads to death!! Their friendships are being undermined by a bottomless terror!!

Adventures of Melty and friends that attend an academy in order to become questers!

Motoko and Keiko are in a relationship. This is their story

Yoshotoshi Heion was a 1st year high school student who had no desire to excel--and liked it that way. In fact he chose Hiyotani High school for that reason. It was an average school only 5 minutes from his house. There's even a cute girl in his class, Rina Fujimoto, and he's already given up on her. But Rina wants to join the "Wind Orchestra Club" (Brass Band Club) only to learn it's been disbanded. Rina's passion for music inspires Yoshotoshi to help revive the club. "Once you make the first step... Who knows what will happen?"

From Alice Dreams:

Misaki Sakurako is a thirteen-year-old girl who loves ice cream and cherry blossoms. Living alone, she had a weird dream that told her she is the only savior to three young child boys... Strangely enough, she woke up to three handsome strangers who asked her to resolve their dear curse--their bodies will transform if they see any slightly "perverted" materials (posters, pictures, etc.). The only way to prevent them from transforming would be...?

On August 10 of 2019, humanity received a signal, which was verified for its integrity by hundreds of scientists, from an alien life form containing one message: let us meet on Mars on July 7, 2035. Thus began the creation of a space agency representing Earth as a whole named ST&RS. From there, things progressed quickly with man re-landing on the moon in 2022 and constructing many space stations orbiting Earth and the moon. The Space Academy was created to train the upcoming generation of ST&RS.

The same August 10th that Earth received the message, Shirafune Maho spoke his first words and it was “Mars.” Since then, Maho has been an astronomy freak who has nothing but the universe on his mind. He decides he is going to apply for the Space Academy along with his childhood friend, Hoshihara Meguru, and recent transfer and super smart classmate, Amachi Wataru. The trio begins their almost impossible journey of being accepted into the school where only 1% of the applicants are allowed into the academy.

Ichina is a 2nd year high school student. She lives with her mother Youko whom she hates with a passion. After getting dumped by her boyfriend, she ends up having a one-night stand with her best friend Sekitani, who also recently broke up with his long-time girlfriend. Will they become more than friends? And who is the strange guy who's waiting at home with Youko when she gets back?

The desirable Tsuu-chan from Yogoreteru Hima Nanka Nai is a character in this story as well.

From Chibi Manga:

Hiroko never had the experience of having a boyfriend. She started recently to lie to her childhood friend Tomoko who pretends that she had a lot of boyfriends...

Then Hiroko starts to have feelings for Takeru who's in the broadcasting club like her.
But when she tried to approach him at the school festival she suddenly discovers the truth...

Takuma Miyabe is a boy from an island who moved to Tokyo because his island doesn't have a high school there. However, the ratio of male and female is 1:9. There are too many female students in his class, and as a result, they "flirt" and torture the still innocent Takuma.

From Okazu:

Mermaid Line is a collection of stories that ran in Yuri Hime magazine. They are collected together as short mini-series, done in an episodic, almost soap-opera-y way.

In "Megumi and Aoi " Megumi confesses to her friend Aoi that, despite her ungainly swimming, she feels as if she is a mermaid. Aoi finds herself fantasizing about being the prince to Megumi's mermaid, but Megumi runs to the arms of a boy, trying to put a beard on her feelings.

Ayumi, in "Ayumi and Aika," wants to get married to her boyfriend so naturally, she's shocked when he tells her that he wants to become a woman.

"Yukari and Mayuko" are both OLs. Mayuko's between boyfriends and bored, so she asks Yukari to pretend to be her girlfriend. It works out well, until Yukari realizes that her feelings for Mayuko are more than just pretend.

In "Girl*Girl," an extra story in the "Megumi and Aoi" Mermaid Line series, Aoi contemplates what things would be like if she or Megumi were guys.

And finally, in "Miura-san and Me" Okabe loves Miura's beautiful hair. When Miura-san cuts it all off, Okabe learns to love her for herself.

From Shoujo Crusade:

Miki always gets turned down so she frequently seeks consultation in love from the convenience store's shop assistance Azuma. Will that be all their relationship ever be?

From MangaHelpers:
Minami Eita lives with his older, book-loving brother, whose long-time girlfriend Arumi is often around the house. Minami tries to get along with Arumi, but the truth is that he likes her much more than is appropriate. Even though Minami doesn't read much, he helps in the library with his bookworm classmate Shinonome Yuuko, who loves short stories. She thinks that while most people want to think of themselves as the hero of an epic saga, short stories are much more like their actual lives. Minami's ordinary life becomes more confusing when he begins to suspect that he has feelings for Yuuko. One day, he finds out her secret--she is actually a published author of short stories! Her publisher wants her to write a novel, and she has enlisted Minami's help in an unexpected way. Minami's teenage life is not going to get simpler anytime soon.

At the young age of 18, Erai Tenka is the president of a highly successful IT company and is filthy rich. He has everything he wants, except for one thing: a girlfriend. The truth is, he is desperately shy around women. He is attempting to get over his shyness by hanging out with a team of bunny-girls, but it hasn't seemed to help.

One night, Tenka goes out walking alone and is very nearly mugged. Luckily, a girl shows up and rescues him, and Tenka falls in love with her at first sight. It turns out that she's a student at his little sister Yuika's high school, so Tenka enrolls immediately. Unfortunately, his crush, Himuro Sai, thinks he's a creepy, perverted stalker, and he's too flustered around her to explain himself! He'll have to get over his shyness if he wants to have a chance to win Sai's heart!

Seven men have entered a school exclusively for girls. Irie, a man who fantasizes about his own harem, feels a great dislike towards Koga, the No. 1 popular ikemen at the school, so he always try to avoid him... But a rumor starts to spread that Koga liked Irie"...!? The garden of a pure maiden opens, to make way for a love battle! An extraordinary high-school love story!

It has always been a one-sided love for Kima. Kima had slept with many guys since high school. However, Furudate was the only student he'd ever loved. Neither has he done it with Furudate before, nor confessed his love to him. One day his mother's lover, Ishiki, appeared before Kima... and so, this unbelievable yet physically and mentally heartbroken love story is presented!

Natsume Kanade wakes up with a terrible headache from the day before unable to remember who he is. Being confronted by a strange man with dark-rimmed glasses who calls himself "God" and being told that he is a high school teacher doesn't help. Stranger yet, everyone seems to know what happened yesterday - everyone except him.

1-4) Continuation of Nemurenu Yoru ni Nomikonda Hoshi from Ukkari Cherry.
After finally winning Sawa's heart and becoming his lover Shiroi still can't let himself be at ease--the more he's with Sawa, the more he realizes how frighteningly close Sawa and his best friend Micchan really are. And it doesn't help that Sawa seems to invite Micchan to go with them every time they can be alone. How can Shiroi make Sawa prove that he's really number one in Sawa's heart.

5-6) Love Letters
When Kotera was in his 3rd year of middle school he got a confession from a guy 2 years younger than him, unfortunately his friends where hiding in the bushes watching. Causing the younger boy to bullied relentlessly by his classmates. What will happen years later when they meet again?

7) Kira Kira
Miyoshi has been with Maki since high school and years later they've started dating and now living together.

Extra
Micchan gets a confession. What are his thoughts on the confession and on Shiroi and Sawa's relationship?

From Liquid Passion:

1-4) When Ryuu transfers to Hitomi's school, he leaves an immediate impression on him. Curious about rumours of a full-scale tattoo on Ryuu's back, Hitomi starts getting closer to him. Before long, the friendship and fascination Hitomi feels for Ryuu start developing into more, but before he has a chance to come to terms with his feelings, Hikaru appears on the scene.... and he has his eyes set on Hitomi.

5-6) Now that Hikaru has become close friends with Hitomi and Ryuu, the group dynamics have changed. When Hikaru expresses his growing interest in Hitomi, will Ryuu admit his feelings or let Hitomi slip away...?

7-8) Ryuu seems to have found comfort in other places as Hitomi and Hikaru Taira get further involved. Sexual frustrations finally find an outlet, though misdirected.

9-11) In a startling series of events that lead up to Hydra's transfixing climax, hearts break, enemies resurface, and ties of friendship bind the trio in a complex web of struggle, sacrifice, and redemption.

Part of Rules / Hydra Series

Kotarou Hayasaka is a new student at Oomiya High School, a prestigious boys school where the student council president is able to make a single school rule at the beginning of the year. This year, the student council president Izuki Jinguuji decides that all the students have to cross-dress during school activities, much to Kotarou's dismay.