From Aerandria Scans:

During the time when the world is full of barren lands and big ships sail out to the vast oceans, a very rare type of sub-human--mermaid--was born. Normally, they have white hair, but only in water does the color change. Among the aristocrats, they are traded for large sums of money. Hisui is a merman with scarlet hair, and he's kept by a lord. However, as he's stolen away by the pirate Ikuta and gains freedom, they start their journey together!

Himeno's chest hurts if any boy touches her because her heart is a diamond. However, when she was young, she befriended two boys--gentle Mamoru and blunt Keigo--who could touch her without harming her. Without knowing about her diamond, both Mamoru and Keigo promised to protect Himeno. When some people threaten to take Himeno's heart, who else will protect her but her knights?

From Nekohana:

It all starts when Tomoe's hair gets caught in Kouga's button. As if by a red string of fate, they're tied together. Through a twist of that fate, Tomoe is forced to work in a house of prostitution lead by the yakuza, and who might be one of the yakuza heads, but Kouga.
Funny and dramatic, but more innocent than you think.

Kataoka (male) and Sato (female) have been friends since they were little. Kataoka has much better hearing than the average human, and he says Sato's voice is the most noisy of all. He has grown into a teenager able to hear everything from far around him--the good and bad. Now that the two of them are teenagers, Sato is affiliated with the school newspaper club, and Kataoka has mostly isolated himself. When the newspaper club decides to look into the truth behind some 'supernatural' rumors, Sato manages to convince Kataoka to lend the club his abilities.

From Chibi Manga:

Shinji, Manabu and Chinatsu are neighbor and childhood friends. Because they hide their thoughts from each other, their feelings became lock inside their heart. At that time, Manabu informed the other about "those things". He could trust his friends forever, but what will happen when they grown up and start to change the way they feel about it...?

Included is the oneshot: I Just Love You.

The continuation of Miiko Desu!
This time, Miiko is in the fifth grade, and the stories have become more exciting!

This series received the 1996 Shogakukan Manga Award for children's manga.

From Intercross:

♥ Kiss to Koukai (Kisses and Regrets)
The distance between us wouldn't diminish. It's painful, lonely, and my heart squeezes in pain. At that time, if I had been more honest, would it change anything...? Yeah, right. That's why this time, so I won't regret it, I'll...

♥ Itoshii no Senpai-sama (Beloved Senpai-sama)
Hinako is the only girl to receive special attention from Katsuragi-senpai, the popular Kyuudo club president protected by his male club-member guards from all girls, not just fangirls. But Hinako's preferential treatment resembles nothing so much as a senior's spartan training of a junior. At first happy over how Katsuragi-senpai diligently takes time to teach her "many things," Hinako later questions why her so-called enviable position saddens her.

♥ Ikenai Koto (Something I Shouldn't Do)
Yui vehemently refuses to have her little brother's friend Haruka stay over at her house for the three days his parents are away...

♥ Kimi no Button Kudasai (Give Me Your button)
Yuki plays pranks on Tomoya because she likes him. Her last one before they graduate — writing Suki (I like you) on the back of his gakuran's second button. What is Yuki supposed to do when Tomoya says "Yes" to another girl before graduation?

♥ Kieta Hanbun, Nokotta Real (Half Gone, Love Remains)
A broken school festival sign and a common love for music makes best buds out of Naru and Yamato. That is until Naru loses all hearing in her right ear and she keeps her condition from Yamato a secret...

From Temptatious Taboo:

Normal high school student Riku comes back home one day to find... she is now the school chairman of a famous elite school?! It seems her grandfather left her the post after his death and, although Riku is not really enthusiastic about the idea, there happen to be two really interesting guys that attend that same school...

Also contains a side story called Kimi no Te to Hitomi to (Your Hands, Your Eyes) in volume 5.

After the death of the Emperor, the country of Li is plunged into civil war. In order to save his brother's forces from imminent defeat, Xueya, 7th prince of the realm, enters into a marriage with the feisty pirate princess Jin Bi Hui. Will her reinforcements arrive in time to turn the tide? Will this political marriage survive? What would Bi Hui do if she found out Xueya's heart belonged to another?

This manhua based on novel with the same name.

From AOC Translations!:

The Asahina brothers chase around our heroine, causing a bit Purupuru ruckus! Experience BroCon in a fresh-new style!

The 4-komas retell the events in the light novel in a hilarious twist.

The seven teenagers who committed crimes had their body parts related to the crime they committed taken away and was sent to a school with a locked room. To return to their normal lives, they have to continuously take the examination and graduate as the first in class within one week, or else...

From Aerandria Scans:

His name is Itou Hiroyuki, nickname: Hiro-kun. He's a math teacher at the private Taihei Academy, as well as the homeroom teacher of class 3-3. He's young, cool, and tall, and yet, when he's with the male students, it's impossible to tell who are the students. He's the person I love.

This is a sad and gentle story about the 15th winter of a girl who fell in love with her homeroom teacher.

From Osuwari Team:
Uni is a prodigy with a cool reserve who is accomplished in everything except for English. One day, she insults her temporary English teacher and he overhears her. He asks her to come to his office after school and, somehow, she starts receiving private tutoring from him.

From MangaHelpers:
One day, Matsui Sakura receives an invitation to a "Revenge Game," and decides to attend. At the location indicated, she ends up locked in a dorm-like building with four of her classmates. It appears that the Revenge Game is being run by a wealthy classmate, Saionji, who was bullied so badly by some of the students that it ruined his life. Now he is taking his revenge, in a brutal game that allows him to have one of his former tormentors killed each morning.
However, Sakura--a lonely, quiet, orphan girl--does not understand why she is there, unless it was due to her inaction in stopping the bullying of others. She's also the only one who received an invitation, while the others were abducted or tricked into attending. What is the final purpose of this game?

From Sound of Jewels:

Kingyo is the most lovely name in the world.
She was my stepsister. She had the most beautiful smile.
She was a crybaby. She was so kind that I couldn't bear it and
...I crossed the line.

In an organization of professional killers called Thanatos, there exists an elite assassin. His skills are such that he reigns supreme over all the others in the organisation... And he is also the killer of the protagonist's family. The protagonist swears on his life that one day, he will rise through the ranks of Thanatos and challenge the man who took everything from him.

Fighting for the position of No. 1, the curtain rises on a battle fought with blood over blood!

From Antisense Scanslations:

Sougo Amagai has no friends at school and spends day after day alone. The only thing that gives him comfort is the feather memento a girl gave him years ago during a traditional dragon dance. Her bright smile is also engraved in his memories. Even though so long has passed, that same feather will bring them together again in the world of dragon dancing.

A collection of oneshots by Hatsuharu, including I Wake Up With Your Kiss, Love Equation, The Flower That Blooms Within You and Me, and Our Sound.

Wake Up With Your Kiss
I have been looking after the helpless Haru for many years now as a childhood friend. He can't take care of himself, yet he's talented at soccer. I always watch senpai, who I have a crush on, while also keeping an eye on Haru. I don't want senpai to misunderstand my relationship with Haru...

Love Equation
I love studying, but a classmate has told me that I should take interest in love as well. Then, there's this certain boy that persistently begged for my assistance in order to tutor him, as he seems academically challenged. Reluctantly, I accepted, spending my spare time with him tutoring at the library. As I tutor him and at the same time, getting more acquainted with him, I start to have these unknown feelings for him...

The Flower That Blooms Within You and Me
I'm a very popular girl at school that makes any guy's heart flutter. I have yet to meet an interesting guy, until I encountered a certain member of the gardening club...

Our Sound
I think everyone has their own tempo. Mine happens to be slower than others, which does often get me in trouble. On the other hand, Fujishima-kun, a classmate of mine is a somewhat opposite to myself, where he is often energetic. When I heard a beautiful sound from a piano, I was surprised that it was Fujishima-kun himself that was the player. Ever since then, I was closer to him than ever before...

Original webcomic A story about a guy who lost everything, and a girl who had nothing

From Manga Box:
“I have lived the past twenty years enshrouded in fat and negative energy." Marina is a gloomy young woman who has failed every diet she has ever tried and can't make friends, much less a boyfriend. But, one night, she encounters a gorgeous man… With a voice as gentle as a beautiful flower, he whispers to her words as sweet as honey: "Why don't you take a chance with me? I'll make your wish come true." Did God take pity on her and send an angel to grant her wish?! Is the man extending this helping hand to our pudgy Cinderella truly an angel? Or is he not what he seems? Strap in for this thrilling rom-com about a hot rich boy and a pessimistic chubby girl!!