From Yuuki Megane Scans:

Shuuhei, Harumi and Daiki start their second year of high school with an absolute goal: Getting at least two new members for their swimming club to keep its position as a club. This is the daily struggles and shenanigans of a high-school boys' swimming club!

From DrMaster:
After his mother's death, Kuro Takagi transfers to Yotsuji Private High School where his father is the proprietor. But Yotsuji is no ordinary school. It holds a strange rule of “No students on campus after dark!” On his first day of attendance, Kuro and his classmates inadvertently break the school’s highest protocol and find themselves victims of a faculty zombie attack. Although they manage to narrowly escape, this is but a prelude to more encounters with the undead, especially after Kuro discover his own blood-ties and latent zombie abilities. From there, it's full steam ahead as this dark and intense action/comedy shifts into high gear.

From Shoujo Manga Maniac:
In a school where students are into different classes based on their grades, there is a prince who is the idol of the school, a cute and shy boy called Renjou Kaoru. Amakawa Yumi, a second year student, doesn't seem to be interested in him though. She's already in love with Kokonoe Yukito, a guy in the same class as her and a childhood friend of Kaoru! What she still doesn't seem to know is that the cute and shy little boy is not actually as he appears to be...

From Aka Roze Tenshi:

Sara is a member of the Heaven Expedition Team, and her job is to hunt Devils, but she hasn't caught even one devil yet and if she doesn't catch one she will be expelled!

She decides to summon a devil so she can catch him, but what will happen when she meets the charming devil Rembrandt?

Also contains:
Midnight
Blooming Love

Following each chapter is a small side story. The fourth side story remains untranslated.

From MegKF:
A senior high school student, Yi-chen, is a girl's comic lover. She likes to draw girl's comic and share them with her friends who joined the "Comic Association" in the school. Ching-ching, Yi-chan's schoolmate, draws shoujo manga very well, and thinks that "Comic Association" should not necessarily exist because their drawing level is too low. Yi-chan is very angry and bets that she will win Ching-ching in this year's "Manga Competition" otherwise the "Comic Association" will be terminated. At that day, she met a boy, Cheng-yio, who transferred to her class. Although Yi-chan did not agree, Cheng-yo moved in Yi-chan's house by coincidence.

Iri and Yukimi have been best friends for two years, and they have something in common--both of them have crushes on two of the coolest guys in school! But they both decide to change that. Iri talks Yukimi into making a game out of it. They'll both do their best to confess their feelings to their crushes and see what happens. But then, Iri begins to make more progress than Yukimi...?

1. Ore no Mono ni Nareba Ii
The sweet love between a genius chocolatier and a trouble-making kouhai.

2. Complex Love
Tomoki enters the school's Boy's Beauty Pageant to find out his rival is the "Perfect Prince" Shiratori who says to him, "If I win the pageant, please go out with me!"

3. Makezu Kirai mo Suki no Uchi

4. Kyou Koso Kimi to!

5. Otona no Koi no Kudokikata

From Forbidden Garden:

1) Cream Caramel
Because her parents are transferred away due to their jobs, Mikoto, a grade 11 student, starts living alone on 100,000 yen per month. But the place she lives at is a horribly old apartment... And the one living in the room next to hers is a super cool boy...?!

2) White Summer
Mana and Shou have to go their separate ways after graduation, will they be able to stay together when they're hours apart?

3) There Are Days Like That, Too
Sonomi has been in love with Ikuta-san since she was in the seventh grade, four years before this story takes place. Ikuta-san suddenly starts working at her uncle's cafe, and it seems like Sonomi might have a chance to be his little sister, since he's been going out with another girl for those same four years that she's loved him.

From Dan of Population GO:

Ooba Asa woke up one morning and became an invisible man. It isn't just him, but various students around school have been gaining superpowers while his little sister has been losing the same powers. Supposedly the student council president is giving out superpowers, Ooba Amime's powers, so Asa, Amime, and the grudge-filled flame girl, Daimon Yaki, form an uneasy alliance to give the mysterious student council president.

Contains 9 stories pertaining to love and friendship.

1. Kimi no Nokosu Toumeina Ao
Two friends spend their last summer days together before one of them moves to a completely new town and school.

2. Okama Kata Emban
A student secretly pines for his teacher. A fellow student advises him to confess, but with graduation fast approaching, he might not make it in time.

3. Hole Memories

4. Promise

5. I'm Real

6. Daisuki Daisuki
A clumsy and highly optimistic student develops feelings for his classmate. While he thinks there is absolutely no chance, it may take an unexpected event to prove otherwise.

7. Nearly Drowning My Honey~

8. Sweet Harvest

9. Confession Day

In order to become a splendid devil in Hell History, a stubborn and reserved 6 year old, Robin Verall, will be entering Hell Academy elementary. He really hates to go to school so he hides in some weird places, resulting in him "being in a pinch!" Robin's homeroom teacher, Shiba-sensei, discovers him in an odd place and saves him from a pinch, and since then, Robin is feeling a bit more attached to sensei than ever. And goes through some Hellish schemes to tries to get closer.

From Intercross:

Eishi is one of those popular guys that are smart, good looking, and is good at sports. However, he thinks people and "love" are bothersome and would rather not deal with either of them. When his teacher told him to help this girl, Uta, to study, he dreaded the idea of having to stick with such an annoying girl. Soon, though, his heart starts to lighten up towards her.

[From StudioRobb]:

It's the story of a young student named Sahra who comes from a broken home. He has a difficult time getting along with his classmates (or, more precisely, he doesn't *want* to get along with his classmates), until a girl named Mai Omi decides to make her mission to help him feel accepted.

Included in Otoko no Ko Comic Anthology: Zettai Fukujuu-hen.

Miyakuni likes his sensei, Sakuma, and is willing to do anything to prove it. But just how far will Miyakuni go to show his devotion?

Sakuma-sensei is an easygoing high school teacher, who has only one student that listens to him seriously - Miyakuni Shuu. But why does Miyakuni pay so much attention to him?

One day, Sakuma finds out the reason for Miyakuni's seriousness, when Miyakuni corners him during lunchtime and confesses his feelings. Sakuma turns him down immediately, because Miyakuni's just a student, but will Miyakuni's seductive expressions wear down his defense?

Chapter 4. Diary of a Faithful Dog
A story about childhood friends... one is obsessively in love and a loyal dog, and the other kind and pretty... so what could go wrong? Maybe a violent reaction to jealousy...

Chapter 5. We Just Can't Help It
Two friends are constantly fighting... and having sex. But that's all it is, right? Horniness after the adrenaline rush...

From Intercross:
Runa has always had a fear of boys. When she's confronted by a confession from the school's most popular guy, Kizuna, she just burst out in tears. However, she calms down when Kizuna says he wants to start out as being friends.

1) Candid Love Proposition
Takizawa is constantly being hugged by cute younger classmate Teru. Takizawa's gotten used to the attacks, but why does Teru do it?

2) His Tutor and Him
Yuuichi is Naoto's strict tutor, but also his sweet lover. But why is Yuuichi on a date with such a cute girl?

3) Arduous Love Journey
Takumi is so cute he's always being molested by guys at his all-boys school. Childhood friend Ei-chan loves and protects him, but Takumi has developed a fear of sex!

4) A Mutual Embrace
Identical twins Fuuma and Raiha have a very close relationship, but upperclassman Taiga isn't going to give up on Fuuma. Twincest alert!

5) Take Out Happy
Kazuya is dumped and goes on a drinking binge. When he wakes up, he's in the home of single parent Fumihiko. Kazuya finds himself spending more and more time with Fumihiko and young Shunsuke.

6) Very Very Happy Days
Continuation of Take Out Happy.

From AQUA Scans:

Cornered by delinquents, Katanabe Shino was just waiting for her end... until Tachibana-kun, her bad-tempered classmate, saves her. She then decides to give him a not so chaste "thank you gift".

Eitoku High School Freshmen Ganya Sho and his classmate, Ryukawa Yuu, who is also a pretty boy, neither of them can stop quarreling with each other. However, Sho's twin sister has a crush on Ryukawa. A track runner and a film star. How will Sho and Yuu's friendship and dreams progress?