By day, Kusakabe Maron is an ordinary high-school girl with more than her share of problems. But by night, she is Kamikaze Kaito Jeanne, the reincarnation of Jeanne d'Arc, also known as Joan of Arc. Her mission: to hunt down demon-possessed paintings and exorcise the evil spirits! Too bad accomplishing this mission puts her into conflict with the authorities, who view her as a mysterious stranger vandalizing works of art. With only the help of angel-in-training Finn, she must survive high school during the day and battle evil by night!

A series of light novels ispired from the manga has also been published in 2013, written by Matsuda Shuka and illustrated by Arina Tanemura.

One day, suddenly... a night where the moon shines like never before, a boy meets the otherworldly Serin, a denizen of Chaos, only to die and become the undead. Now immortal, he can no longer exist with humans due to an ancient law... A tale of revelations that begins as he returns to Chaos, the start of a new adventure!

From Operation Boredom:
Yamato Onidzuka. Childhood bully, punk, and sports prodigy. His old childhood friends are terrified of him, as he used to bully and harass them on a daily basis. When he transferred to a special sport's school, it seemed like his friends' worst nightmare had finally come to an end. But now that he's back, it seems like the nightmare has returned.

From Aerandria Scans:

Kei is a girl who's only interested in other girls! However, tricked by her mother, she enrolled in an all boys school, thinking that she'd be able to make her high school debut at a co-ed school. To normal girls, being surrounded with hot guys at an all boys school might be heaven, but to Kei, this is hell! What is Kei to do at this place without any other girls, where she has to try her best to keep her real identity a secret?!

What is a sweet, soft-spoken girl (Ha Li Kang) to do when her brothers, having just learned fencing and martial arts, decide to test some moves out on her in order to "tame her" and make her into their "little slave?" She runs to her knightly friend (Te Hu Kang, not related to Ha Li) for protection, of course. However, what happens when, instead of comforting her, he tells her that she is a coward for running away like a puppy who needs constant protection? No, she does not break down and cry like a weak girl. Instead, she resolves to grow stronger. With rigorous training everyday, Ha Li goes from being a scared girl who cries for help to becoming the Jjang (boss of a gang) of the Doberman gang. However, events lead to Ha Li getting in an accident with a truck. Afterwards, she is reborn into the body of a beautiful, but weak, rich girl Aram Han.

At her new school, everyone is surprised at the sudden change they see in Aram, who has gone from a gloomy, good student to a rude, carefree troublemaker. Many people bully her. When Ha Li finds out that it is all due to Sin Uoo Park, the handsome prince and Jjang of the school who detests Aram, she decides to have a duel with him for the position of Jjang. What will happen next is for you to find out in this romantic comedy Korean manhwa.

1) Zenbu Shiritai
(I Want to Know Everything)
I won’t act spoiled in front of my boyfriend, and I definitely won’t trouble him, either. I’m trying to act like a cool and mature ideal girlfriend, but the truth is, I’m a persistent and annoying girl who wants to be pampered by her boyfriend! Even though I'm hiding my true self from him, to satisfy my evil desires, I’m stalking my beloved boyfriend!!

2) Sakasama Honey
(Upside Down Honey)
Kameyama Chisato is a girl without boyfriend, because of her sadistic personality. While trying to fix it by secretly practicing with a skeleton in the Biology lab, a classmate named Kurosawa Akihiro sees her. What will happen to her secret?! Will Chisato ever find love??

3) Chiru Chiru Michiru
(Fall, Fall, Rise/ Broken-hearted Michiru)
Michiru is a girl with poor luck when it comes to love. She’s been dumped several times by her boyfriends for other girls. After her latest breakup, she feels really dejected. In her attempt to get over her love, she pretends as if she's about to commit suicide. However, a boy from her school, who is rumoured to be a delinquent, stops her, and promises her that he’ll introduce her to the best guy on earth. Just who is this 'best guy on earth' and where can he be found? Or is he right in front of Michiru’s eyes?

4) Ashita Hanabi ga Agattara
(When There's Fireworks Tomorrow)
Tomoe has a dreamー to go to the fireworks display during the summer together with the guy she likes. However, she hasn’t found that spark of love at all, at least, not until her childhood friend, Miki, moves back to her school and she meets Kagami through him! She makes the perfect plan to confess to him, but that doesn’t go as well as she had hoped, when Kagami confesses to her that he really likes Tomoe’s best friend, Rikka! Is the friendship ruined between these best friends now? And will Tomoe be able to fulfill her dream of watching the fireworks with someone she loves?

5) Super✰Star
There’s a certain group of guys in Kiyoko’s class that stands out, and to Kiyoko, Hoshino stands out the most! In fact, whenever she sees him, he looks like he’s sparkling. However, Kiyoko realises that Hoshino isn’t exactly what he seems to be, when she discovers him working at his family’s run-down convenience store! But even in his dull work clothes, Hoshino is still sparkling to her. But it’s not until Hoshino is confessed to by another girl that Kiyoko truly realizes that even if she’s different from Hoshino’s ideal girl, she still has a chance… but is it too late now for her?

A regular school boy, Hikaru Shindo stumbles upon an old GO board while looking through his grandpa's old storage room for something worth money. From inside the board came an old spirit named Sai who once dedicated his life to GO. Together, Sai continues to search for the move people call "The god's hand" while Hikaru slowly began interest in this ancient game and walks down the road of GO.

Won the Shogakukan Manga Award in 2000.

Contains 3 short stories:

Chapters 1-3 - They'd been drunk. Or, more specifically, his boss had been drunk. So when Sakamoto jumped him, Kurahashi just went along with it. After all, it was just the alcohol...right?

Wrong!

At least, that's what his boss thinks...and said boss doesn't have a problem trying out a relationship with a colleague he thinks is in love with him. Unable to gainsay him, Kurahashi gets dragged into a relationship he never asked for - and finds himself getting deeper than he ever imagined.

Chapter 4 - Two childhood friends who abruptly drifted apart years ago are reunited. One of them is now a Buddhist monk... What does his friend feel about this?

Chapter 5 - The shy, reclusive, bespectacled Egawa confessed to Aoki on high-school graduation day...and was politely turned down. The two unexpectedly reunite in university, but to Aoki's surprise, Egawa has become a completely different person who's very popular with the ladies! But why does this cause strange, conflicting emotions within Aoki?

Hardworking level one magician Konoha is apprenticed to lazy Knight Protector Saionji Ikumaru. They both work to keep the ether world sealed away from their own but sometimes the seal doesn't work. Dragons, demons, and now Ishtar, the goddess of Venus. Will Ishtar help Konoha win her master's affections? Or will she take him for herself?

From Wild*Hope:

Miyako, who has undergone strict training, is the heiress of a rich family. However, the person she loves is her distant cousin Chiaki, who is her complete opposite. Miyako's mother has always been opposed to their relationship and arranges an omiai for her. Just when Miyako prepares to elope with Chiaki, she finds out that he has already left...?

From ShoujoMagic:
Shinjo Mayu's newest leading lady is an idol, and the leading man is... a future prime minister!? Just what is a "Love Celeb"? Nakazono Kirara is an aspiring starlet. She used to think she'd do whatever it took to get a starring role in a drama and have a CD. But her manager, Hanamaki, proves her wrong when he sends her into a room full of horny producers to sleep her way into a role! Kirara wants no part of it! She's a virgin, and these guys are scary!! Especially the silver-haired one named Gin... He seems to be in charge. But he lets Kirara leave the party with her virginity and his phone number, and it seems like nothing lost, nothing gained... until Kirara is suddenly the most famous new starlet for no apparent reason!?

Side story in volume 7: Darenimo Ienai!
Ruka’s a junior high student in love with her father’s assistant, Fumi-sempai. She wants to become an adult quickly because everyone sees her as a little kid! But what would happen if she actually became an adult with the help of a time machine?

From Prisms:

A romantic comedy about Fuwa, a guy living in a small apartment in overcrowded Tokyo, who wants to have a place of his own. Because of a building accident in their new office building, Fuwa's company (5 employees) had to move into his apartment, right after he had moved to a larger place. And the new employee (Hiyama Izumi, a 15 year-old girl) had to move into Fuwa's place, as she had just come from the country. Then Fuwa's old girlfriend Tokiko, who had already gotten married, ran away from her husband and came to Fuwa's place.

From RebelliousArt:
Asahi, desperate after the loss of her best friend and boyfriend, came to the abandoned elementary school above the hill. It has been said that it's a cursed place that it will be the last place you will tread in. Those who live will not be able to return. And there, Asahi meets...!?

A series of oneshots.

Sana Kurata, a child actress, faces many problems in her classroom, including a major one - her bullying classmate, Akito Hayama. Sana's outgoing and friendly nature leads her to work towards correcting all of the problems around her. Her 'meddling' irritates Hayama but at the same time captivates him, just as Hayama's gloomy nature irritates Sana and compels her to change him. As these two opposites attract each other, they face many hardships which bring them closer to a mutual understanding.

This manga won the 1998 Kodansha Manga Award for shōjo.

Daisuke is a 23 year-old new schoolteacher. He ends up being put in charge of a 3rd grade elementary school class since the previous teacher quit, and in that class there's a girl who's quite a troublemaker--Rin Kokonoe. You could call her a masegaki (used to describe a kid that acts more like an adult in some ways), and she's also part tsundere (though more dere than tsun).

Peace seemed to have finally found its way into the Obinata household, but through an unexpected turn of events, Shuu and his adopted son, Yuuta, are faced with a disagreement that might change their forever. When their respective lovers, the eldest Obinata brother Taiga and Mayumi, the youngest, are dragged into their conflict, and Yuuta runs away from home, the whole family's living arrangement gets off balance. Will the peaceful days ever return?

Mainichi Seiten series:
Vol 1-2 Mainichi Seiten
Vol 3-4 Kodomo wa Tomaranai
Vol 5 Children's Time
Vol 6-7 Kodomo no Iibun
----Aki-chan no Iibun
Vol 8 Isoganaide
Vol 9-10 Hanaya no Nikai de

From Del Rey:

Najika is a great cook and likes to make meals for the people she loves. But something is missing from her life. When she was a child, she met a boy who touched her heart–and now Najika is determined to find him. The only clue she has is a silver spoon that leads her to the prestigious Seika Academy. At Seika she meets two brothers Daichi and Sora, could one of them be the boy from her childhood?

Won the Kodansha Manga Award for Children's Manga in 2006.

The son of a famous pianist, music student Shinichi Chiaki dreams of studying abroad and becoming a conductor like his mentor. Unfortunately, his fear of flying grounds his lofty plans! As he watches other classmates achieve what he has always wanted, Shinichi wonders if he should quit music altogether.
Then one day he meets fellow student Megumi Noda, also known as Nodame. This oddball girl cannot cook, clean, or even read a music score, but she can play the piano in incomparable Cantabile style. And she teaches Chiaki something that he has forgotten: to enjoy his music, no matter where he is.

Winner of the Kodansha Manga Award for Shoujo in 2004.

Yoshino Nako has a saying. "If I'm happy, I can do anything!"

In her sister's place, Nako-chan steals the groom of an arranged (political) marriage and helps them elope. But when the Hayami group starts failing, she must pay the consequence by housing the delinquent brother...

From Perfect Illusions:

Reo-chan, a first-year girl, gets dumped by her boyfriend because she's not skilled in the home economic traits he believes women should have. Her ex tells her that she must apply to a "housework" club before he will reconsider going out with her. Therefore Reo-chan has little choice but to join.

Here's the catch: the only members are four gorgeous bishies. The other first year in the club, Irinaka, competes with her a lot. As the story progresses Reo and Irinaka get forced into a lot of interesting situations together and in the meantime become closer and closer.