From Shogakukan: Ping pong. Table tennis. Fast, furious. You might have seen it, even played it, but you've never seen it like this! The action centers around "Smile" Tsukimoto and "Peco" Hoshino, two high school students in the midst of adolescence and out to prove they've got what it takes in the cool, cruel world of sports. This manga even got adapted into a live-action movie.

In this school fantasy story set in the distant future, creatures contaminated by pollution have overtaken the land, forcing humanity to live in isolated mobile cities called Regios. One such city named Zuellni is a self-contained school in which freshman Layfon Alseif has just enrolled. Layfon reluctantly joins the 17th Martial Arts Studies Unit led by the third-year student Nina Antalk and embarks on a series of adventures.

An original side story that focuses more on Nina.

From MangaHelpers: Puzzle fanatic Daimon Kaito has been crazy about solving brain teasers, puzzles and riddles his entire life. He attends the prestigious Root Academy with Nonoha, but spends most of his time creating and solving puzzles. Kaito is one of the few genius teenagers that attend the school who has been given the title Einstein, along with his other just as brilliant classmates who were given the titles Galileo, Edison and Da Vinci. Together, they attempt to solve a puzzle that, since its creation centuries ago, has never been solved. But the genius students soon realize that there are dangerous forces behind the impossible puzzle. [vyc]

Pai is a strange, provincial woman who has come to Tokyo from the Tibetan highlands. Somewhere in Tokyo is a young man who can help her in her quest... to become human!
When Pai finally finds Yakumo, they set off in search of the artifact that can transform her, but it will take all of her mystical powers to keep the reckless Yakumo alive, even if she has to steal his soul to protect him!

Winner of the 1993 Kodansha Manga Award for Shounen.

From 200 wpm:

Miyu, an ordinary new first-year student who hopes to become a mangaka meets the schools’ class president who seems to have a hidden side to him. While being pushed around by the cool but private class president, the curtain on Miyu's stormy school life is raised.

Sae is a flight attendant working for ANL (AeroNippon Lines, a fictious airline). She wanted to work in this field thinking on the glamourous aspect of the job since her friends at the university were teasing her about her sex-appeal. She'll discover the truth about being a flight attendant while having to deal with the passengers!

A 4koma based on the video game Ys vs. Sora no Kiseki - Alternative Saga.

All humans in this world can use the power of the light of mana, and those who can't are considered to be subhuman 'Norma.' The world is like a peaceful utopia, and the celebrated princess Angelize leads a happy life. She believes that the only darkness left in the world is the existence of the horrible Norma. However, in a ceremony on her 16th birthday, the truth is revealed--Princess Angelize is a Norma. Now she is going to learn what her society does to Norma. She is sent to an isolated island full of others like her, who are taught that the only reason they are allowed to live is in order to fight to protect the peace of this world. Now "Ange" is part of a squad that pilots Paramails and fights invading extradimensional dragons.

A new teacher finds himself a newly appointed position as a teacher at an all girls school... on an island... in the sky! How will he make do in his new surroundings? Or the residents of this island who seem like they came from another world? And what's more, how will he fare at being a teacher?

From Bakeneko Scanlations:

Munematsu, the manager of the host club that has recently opened in the shopping street of a small town, meets the timid representative for the neighborhood council - Tooru. At first, Munematsu believes he's just a quiet four eyes, but the drunk Tooru is more seductive than expected and Munematsu starts to feel attracted to him. But the reason why Tooru doesn't let Munematsu touch him is.....!?
The comic romance of the handsome host and the plain recycle shop owner!

From MangaHelpers:

Inudzuka Taromaru is a first year high-school student who looks like a delinquent. One evening, while he's at his part-time job, he ends up with a white-feathered arrow through his head! He's told that this arrow means he has been chosen as the sacrifice for "Inugami-Hime," who lives on top of the nearby mountain. However, this mysterious "Inugami-Hime" turns out to be a cute girl who has chosen him to be her servant, not her sacrifice. Their life together is just beginning! [tethysdust]

1) If It's Not You
For Suwa, a hunk like him needs a pretty girl by his side. Theoretically. But in fact, he's going out with Fujisaki, four-eyed and average looking. It's just a temporary relationship for Suwa, only until he finds a girlfriend... But then, why does he feel so guilty when he takes an interest in someone else?

2) Are You Lovely
When Daisuke finds a love letter in his shoe locker, he's over the moon with joy! The handwriting and the girl's name are so cute, her looks are surely as sweet.... or are they? "Ruka-chan" turns out to be a large, effeminate, kendo-club freshman guy! What will Daisuke do??!

3) Two Glasses
Ryuu has a fetish... a glasses fetish to be exact. In a triangle of seduction, Ryuu has to choose between his cute childhood friend Aya, and his sexy co-worker Kuze-san.

4) Moonlight Stroll
Yuuya is stressed out by Tokyo... the city, the company, the trains. He suddenly gets a call from Haru, his ex - who apparently emailed that he was coming to visit? The days with Haru pass, and Yuuya remembers when they were together... how nice it felt.

5) Even a Dog Wouldn't Take a Bite
Yutaka and Yoshi have been going out... but lately Yoshi keeps breaking appointments because of work. Yutaka gets fed up with it, and decides to let of a little steam with the new guy Narazaki...

Wataru starts his high-school life by getting forced to cross-dress by his senpai Ayane Takamura.

Narue is an adorable schoolgirl with a secret. She's really an alien with powers right out of a sci-fi comic! But growing up is never easy, and sometimes it doesn't help when you're from outer space. Join our spunky heroine as she faces androids, alien invasions, and (scariest of all) her very first date!

Note: Won the Seiun Award for Best Comic in 2014.

Collection of short stories about the misadventures of Tomoko Kuroki

The sequel of Kirai ja nai Kedo, Koi ja nai Kedo and Kare Ja Nai Kedo as the fourth story of the Yuki-Shinonome series. Finally the both of them became a couple, but another obstacle awaits them...?! Shinonome finally made Yuki-chan his boyfriend, but wait... the storm is not over yet. Who's that person who's taking Shinonome away to the counselling room? Is Yuki-chan.... feeling jealous?! And why is Yuki-chan's brother here?

From Girls' Generation: Kokonoe is a werecat who turns into a cat when he is excited. Destiny has it that one morning, Kokonoe, runs into Natsume, who seems to have a special relationship with cats. With Natsume's touch, Kokonoe soons finds himself purring and getting excited. However, Kokonoe is determined to keep his cat side and the feelings he has for Natsume under control. How will their love blossom? A love lesson between a white coat school doctor and a werecat.

From Turtle Paradise:

It's not that she tries to keep to herself, exactly: It's just that everyone seems to look right through her! Naturally, Sakuya Tohno has a complex about it. She says she's just like air: ever present, but never seen. All she wants is a friend, but building relationships isn't exactly easy for someone who is, for all intents and purposes, invisible. But then she hears a legend about the "Thousand-Year Sakura" and how, if one makes a wish beneath its perpetually-blossoming boughs, it's sure to come true. So in a moment of desperation, she races to the tree, only to find four very attractive boys waiting for her... And at that moment, beneath the cherry blossoms of the ever-blooming Thousand-Year Sakura, something incredible happens!

From MangaHelpers:

This is the official comic based on the game of the same name. An all-girl's school is preparing to consolidate with another nearby school, which will make them co-ed. Uryuu Shingo is chosen to be a male 'test student' at the girl's school before they officially merge in the following year. On Shingo's first day, he learns that many of the girls are not happy about the coming merger. Specifically, Seno Airi is staunchly opposed and refuses to welcome him to the school. Some of the other girls are friendly, but Airi has a lot of power over public opinion. The truth is, though, that Shingo has met Airi before. When she and Shingo's little sister got lost, he helped them find their way. Airi seemed to like him then, back when she didn't know he was going to be her new male classmate. Maybe he'll be able to win over Airi, as well as all his other interesting female classmates! [tethysdust]