Two brothers, Shunpei and Kyouhei, have very opposite characters but share a crush on their cute sister Anko. The three of them live with their excentric father, may (or may not) have diffferent mothers, have fun, lots of tantrums and try to lead a happy life in junior high school.

From Omanga:

Eiji Otsuka and Sho-u Tajima at it again, Eiji in a much more minor role this time, however. In any case, this a relatively older and short comedy series (4 volumes) that should be a fun break from their usual mayhem with MPD (Multiple Personality/Dissociative Identity Disorder) .

In 1994, this manga was published as a whole under title "BROTHERS High School".

From Boys On Boys Love:

Katou is a member of the high school swim club. Matsuoka has come to bring him lunch and use Katou as his stress relief punching bag yet again. To the sympathy of his club mates, impulsive Katou totally falls for him, saying with a shy smile that Matsuoka is cute… Even as Katou treats Matsuoka kindly and tells him that he loves him, Matsuoka remains a total tsundere, leaving doubts to linger in his heart!

Mizuhashi Nao is a 16 year old, who is shy and friendless. He passes his class breaks in the toilet playing games where he won't be bothered. One day an upperclassman appears peaking from above and with a huge nosebleed that covers him with blood. Her name is Serika. Wait, a girl?! What is a girl doing in the boys restroom? And why did she just ask him out on a date? Nao's world is about to be turned upside down.

Sakurai Sayuki was born with sharp eyes that make her look like she's always angry, even though she's not. Because of her looks, students around her misunderstand her as a bully and scary girl when in fact she's "a romantic". After 15 years without a boyfriend, she started off her high school year with hopes of love...

Also includes:
Yes or Kiss (Volume 2)
One night, Miyu was confessed and kissed by her friend, Ai's, boyfriend.

Keiko is a junior 2nd year student, but has no experience in love. One day, while going to school, she helps an unconscious 'cute boy' who fainted from anemia. Being two-faced, he doesn’t thank Keiko but instead calls her an old lady. Surprising as it is, that boy goes to her school and is a first year.

Also includes 2 oneshots: Never Let Go of Your Hand and Sweet Relationship.

1-2) Chikan Diary
Yuuto is a first year student at an exclusive private school for boys where everyone is a virgin except for the new transfer student Hachiouji. As part of the student news paper it's Yuuto's job to get all the dirty details or else spend the rest of his life as a virgin!

3) Journey of Lost Love
When his lover gets married heartbroken Atsushi decides to take a tropical vacation to relieve his stress. Nothing seems to be working until pushy tour guide Rubi decides to help Atsushi out. But the only thing Rubi seems interested in seeing is Atsushi's body!

4) The Perverted Daddy Long-Legs
Orphan Mizuki is suddenly pulled off his paper route and offered a high paying job taking care of a sick company President. Mizuki's new duties for entertaining the bed-ridden, surprisingly handsome young man aren't quite what he anticipated...

5) An Awkward Kiss
Morihira has issues moving on to the next level of intimacy with his lover Ueda because of a complex with his face, but Ueda mistakes it as Morihira not liking him. Will this pair ever move to the next level?!

6) I Won't Even Lose to Sailor Suits
Shintarou's teacher/boyfriend went to work at an all girls school and suddenly told Shintarou not to see him anymore. What is poor Shintarou to do?! Putting on a girl's uniform seems like a good start.

From Day of the River:

Since her parents are a little bit slow, Matsuda Erika (or Eri for short) has taught herself to be independent and extremely reliable. Moreover, she devotes herself to taking care of those around her—even if some of her classmates find her behaviour overbearing and annoying. One day, a strange new transfer student is introduced to her class. This boy speaks in choppy sentences, has little to no facial expressions, and goes by the name Nokina Kaname. Instantly, Eri feels compelled to take care of this martian-like new boy in her class.

This manga is a revised version of "Kimi to Hatsukoi", a one-shot found in Mako to Aki-chan no Koigokoro.

The oneshot "Kirai, Suki?" included at the end of the story has yet to be translated.

A playboy who has gone through countless girls; a pure, lovely girl whose only love is chicken cutlets; a super gifted student who spouts poetry and songs about fried chicken cutlets; a blond hyperactive boy who chases after girls with chicken cutlet deliveries three times a day; the student council president Wei Luo Li who moves people's hearts everywhere, and also the truth of the BL headline story published in the school newspaper...
The legendary stories happening at Rembrandt High School are just that unbelievable!
Includes side story to "Proud Dragon Showy Phoenix", which was published in Butterfly Likes to Read

Karin is a cute little girl who also happens to be a vampire... with a twist. Once a month, she experiences intense bleeding from her nose-we're talking gushers! In other words, she's a vamp with blood to spare, so rather than stealing blood from humans she actually gives her blood to them. If done right, this can be an extremely positive experience that benefits the "victim" as much as the vampire. The problem is that Karin never seems to do things right!

Tomoki, a young man with a thing for ecchi stuff, is used to living alone, with his dad traveling all the time. However, he is not prepared for the sudden arrival of his 9-year-old twin sisters, whom he never knew even existed! Toujou Minaho, the big-breasted girl next door, is ready to help out, but these cute little girls are quite a handful.... From Baka-Updates: Kamishiro Tomoki is an Otaku who is studying for college. One day, he received an outrageous "package" from his father: 9 year old blond girls who are his dad's illegitimate children from one of his business trips...... The twins, Selly and Riru are completely spoiled and drives Tomoki crazy. Not only that, the sisters have a "secret" plan to kick out Tomoki and claim the house just for themselves. Will Tomoki manage to make peace with the girls? Read and find out!

From Attractive Fascinante:

Kotani found his pace all messed up when the new biology teacher, Fujishima Masato, appeared. Fujishima confessed and Kotani felt scared. Fujishima’s perseverance won and Kotani accepted him. Kotani’s ex-student came back and behaved oddly towards Kotani. When Fujishima couldn’t find both of them, he thought Kotani might have been kidnapped. Was he able to save Kotani in time?

Contains one main story and two one-shots.

The heroine is a girl who has no clue about romance.

Her point of view :
My childhood friend is a cute guy, and he always come to my house in the morning to wake me up. Although he can be quite mean sometimes, being with him makes me feel very happy. But, once the fact that we're not dating became known, many girls began to hit on him, and start to confess. But, it seems that I feel something towards him lately! Whatever should I do now?

Extra 1 : The Witch's Sweetheart
Extra 2 : Victory or Defeat : The Unbeaten Love

Cherry Juice is about Otome and Minami, two step-siblings. Minami is a popular boy who takes cooking at school, and Otome is an average girl who is in love with Minami's best friend. Cherry Juice's main focus is on the love lives of Minami and Otome, who are in love with other people....or are they?

From Forbidden Garden:
Manami, a highschool girl, joined the class party where there was fun, laughter, and drinking. She had the best night of her life until the next morning, when she woke up to find that she wasn't alone. She quickly looks over to see that lying next to her is her "friend" Motoyoshi Hajime. Did they actually do anything together?!! To the inexperienced Manami, her world is turned up-side down as she tries to figure out how to deal with this situation...

Includes:

1. Cherries Fight
2. The Fastidious Princess and the "Mature" Prince
3. Miss Pageant's Anego. Kakei Masumi ran an all-girl gang in middle school. Now in high-school she tries to bury her past, pose as a bookish honor student--and keep a tight leash on her temper. All this is at risk when Ohara-kun picks her to compete in the school pageant. Why her?
4. Secret Incompetent Swordman

From Tokyopop:

Naka is an aspiring young model with a problem: her face tenses up into a terrifying spectacle whenever she gets nervous on photo shoots! Naka's rival is Umi, the hottest model at their agency. But Naka soon discovers Umi's secret--and hilarity ensues behind the cameras!

From Attractive Fascinante:

Volume 1:
Mizuno Chihiro was unable to control his urges and got erect very easily. Because of his constant tardiness, he was sent to participate in the re-development system together with two other problematic senpai, Takatou Shinobu and Kandori Akira. Sharing a room with Takatou, Mizuno became erect when he helped Takatou (a mangaka) on his smutty works. Takatou tried his best to help Mizuno but fell in love with Mizuno along the way. However, he refused to admit his own feelings and hurts Mizuno. What should Mizuno do?

Volume 2:
V2 focused on the love triangle of Takamura Harumichi, Kandori Akira and Takamura's aniki, Akuda Shuuji. Kandori finally found out what really happened during that winter three years ago. With Takamura's confession, would Kandori accept it and move on? And with the help of Kandori sensei, would Takatou Shinobu finally become one with Mizuno Chihiro?

Extra Booklet

NOTE: Volume 1 was released in 2008, then re-released in 2010 along with volume 2.

Sachi goes to an all-girls high school, and is quite the clueless one. At her first goukoun, she meets a boy called Yuki-chan, which finally ends 17 years of a boyfriend-less life, and!? -- Manga Updates

A self-proclaimed angel decides to intervene with a boy's love life, starting with a timer on a boy's arm, which will count down every time the boy's heart beats from interacting with his crush starting from 10. At 0, the boy will confess everything he is thinking at that moment. But it only starts there! The 'angel' has powers based on the number 10, and grand the boy the ability to stop time, make someone fall in love with him, learn who others like, and more. With comedy, romance, and drama, this is not a typical shounen series and should not be passed up.

Seda has it tough. Her school has suddenly gone from a girl's only school to co-ed. Plus, her father could be described as a Korean Scrooge.
But with the boys coming into her life, being late for the bus isn't the only thing she needs to worry about.

Sasami is the type of girl who gets easily pushed around at school. One day, a rambunctious young boy named Kou causes trouble in school and unknowingly drops a strange piece of candy. Sasami returns it to him, and he suddenly asks her to marry him! Will Sasami accept his proposal, or will she completely reject it?

Volume contains: main story (chs.1-3) + 3 oneshots

(from PocketScans)