From Shoujo Crusade:

Yamada Chizuru was a normal high school student... that is, until her mother left for a "journey" leaving her with a debt of one hundred million yen! As if that wasn't nerve-racking enough, Kuze Mitsuru, the Umegaki gang's Sandaime, saves her by buying her to be his fiancee?! What will become of Chizuru's days?

Contains the side story Coffee is a Black Witch.

A collection of short stories.

Viewed by some as a monstrous scourge and others as dark gods, the dragons are almost as ancient and powerful as Odin and the other Aesir, and for countless years have lived wild and free, unbowed and soaring across open skies. But things have changed. The dragons have been tricked and enslaved by the malevolent Loki and the traitorous Nidhogg, the Black Dragon. Now, their only hope for freedom rests with those few dragons who were able to avoid enslavement, one of whom was Iris. With ancient fire burning in her veins and hungry for vengeance, Iris has allied herself with the Einherjar so that she might gain the chance to burn Loki to ashes and free her captive brothers and sisters. Crystal Arena is a manga series based on the strategy game Crystal Arena, a story of the legendary Einherjar fighting alongside with the mighty gods in the ultimate battle of Ragnarok.

From MangaHelpers:
The end of the civil war signaled the start of the industrial revolution in the United States and immigrants from all over the world traveled to find their American dream. But what awaited the majority of them was poverty, discrimination, and hopelessness. Manhattan, New York was full of immigrants flooding through the ports and the 6th district, Five Points, was considered at the time, the world’s worst slum. The mobsters corrupted the entire area, including the police by paying them off; Five Points was the mob's territory and they were the law.
But even Five Points, where there seemed to be nothing but robbery, prostitution, and murder, showed some signs of hope. Luke Burns was an honest and righteous teenager who realized that the mob was the cause of their harsh lifestyle and that joining the mobsters would not bring him the American dream. But his older brother, Brad Burns, had become an assassin for the biggest mob group of Five Points, the Grave Diggers, a secret he kept from Luke for his own protection. Brad was known as the Grim Reaper and his reputation preceded him as a ruthless and skilled killer.

From Fate:
Set in a fictional European country in 1924, a Japanese exchange student meets a mysterious, brilliant girl who only leaves the library to sleep. Her brother, a detective, relies on her mind to solve difficult mysteries, several of which draw her away from the library.

From Manga Abyss:

Yoshino Haruka, 16-years-old, substitutes for her sister at an arranged meeting and ends up falling in love with Kunihiro-san... To discover the day after that he is her new home room teacher! How are the two of them going to deal with this forbidden relationship?

The year is 1949. Japan had been defeated in World War II and was occupied by Allied Forces consisting of American, Australian, British, Indian and New Zealander troops.

A young woman meets a young man. Both have lost everything because of the war. Tome Kano, a barmaid, and Katsuya Ranzaki, a wealthy investor. The two are fed up with their lives and want to live "real lives" for once. Katsuya's starting up an all-girls baseball team with Tome on it allows them to do this. In this dramatic story, the dreams of a nation come alive. Through the determination and strength of Katsuya and Tome, girls baseball becomes a sensation, and Tome a superstar.

From Yen Press:

High King Madeth and his dear friend, the knight Lalvan…

By all appearances, the ties that bind the two men are made of the sternest stuff, but in truth their friendship has always struck a most delicate balance. With the arrival of Lady Prima and then her newborn son, Perseus, the precarious harmony between Madeth and Lalvan crumbles. And years later, when the young Perseus, harboring questions about his birth, seeks out Lalvan, will the repercussions be much greater than a friendship lost?

A lone angel, its eyes replete with sadness, watches the tragedy unfold…

He died, only for a minute. Minakawa Ryo was an ordinary high-school student until the day a girl jumped off a building, killing him with her. He miraculously comes back to life but with a new ability to see and hear what ordinary people cannot. Then one day a mysterious girl, Hokuto Shou, appears and tells him that his half has become a resident of the world of the dead. His previous ordinary life has dissipated, and a new life between the "living" and the "dead" begins.

Included is a special arc called A King and a Baron+.

The history is about a half japanese, half italian man in New York, who works as a contract killer for the mafia

Nobody know where it is, but it's a place that offers shelter to those who hate their lives or are trapped in the labyrinth of their own hearts... a mysterious hotel. Even now, those who are tired of their lives come to stay in the "Kiri no Mori" Hotel...

In 2012, the author released another chapter, not yet included on a volume, as part of the 35th anniversary of Petit Comic.

In her Ay (Aniversary Box - 2013) the author wrote that this work is unfinished.

Hoshino is a timid grade school teacher. Sudou was one year his senior in high school. They meet again for the first time in over a decade and discover that Sudou's son is Hoshino's student. The two of them try to figure out how they feel about each other, and try to remember what it was that had brought them together and ultimately drove them apart in high school. They're both different, but that may not matter as much as how they still feel about each other.

1-2) Oboreru Hitomi
Aki is a male escort. He takes on customers from the shop. Miyaji-san is an ordinary salaryman who becomes Aki's client. He told him he thinks he might be gay because seems to be attracted to men lately. Aki suggests that they first start with a kiss, but ends up sleeping with him. He likes Miyaji, so he gives him his number. Then they meet outside the store...
Note: Chapters 2 and 3 were edited into one chapter in the tankoubon.

3) Saitei Kareshi
Tells the story of Aoi and his client Kaneko, an ordinary businessman.

4-6) Hearts
Tells the story of Shou and their manager Hayama.

7) Telephone
A sequel of all three couples.

From Chibi Manga:

She loved a teacher. But that kind of love is forbidden! Still she kept love him, and didn't care about it.

One day, she met a boy in white clothes in the greenhouse of the school. She saw his kind eyes and she smelled the odor of wood coming from him. For the first time, Tsugumi felt her heart beating for someone.

But after that encounter she understood that this guy was her teacher...!!

Can't find a way to break up with your boyfriend/girlfriend? These people will do it for you.

Kashiwagi has a special ability. When she touches someone, she can see their future romance. But Kashiwagi doesn't know anything about romance herself and can't determine whether the scenes she sees are happy or sad endings. Kashiwagi works at a cafe, known as the "break-up cafe", managed by Sano and in which Konno works as clerk.

From JShoujo Scans:

"I absolutely won't fall for this brat!"

Due to job transfers, Makoto has no choice but to stay at the home of her father's friend for the time being. But there lives a boy who makes her boiling mad!? Turns out he's the king of popularity at school, but he's a prankster who likes to mess with Makoto, and even recently dumped one of Makoto's good friends! How is Makoto supposed to handle this obnoxious brat!?

Every day in Japan, 2500 people die due to any number of causes. Do you think you'll be one of the ones to die? No, of course not. Do you think you'll win the lottery? You'd like to think so, we all would. But Sumida is different. He wants the status quo to remain in every way; live a normal life, get a normal job, have normal kids, never to be anyone fortunate or unfortunate, content in normalcy. Anyone who doesn't agree is foolish, doomed to live their life scraping up a mountain that they can never conquer, fated to die in despair wishing things had been better.

When his mother kicks his father out of the house and onto the streets, he thinks he'll be fine. When his mother leaves him to live with her boyfriend, he makes the best of it. When he realizes that he's no longer average, he strives to make his life worthwhile the only way he knows how. When the demons in the back of his mind speak to him, he tries his best to ignore them.

K, a robot detective, joins the Tokyo Metropolitan Police Force’s Science Division and is partnered with human partner, Shinjo Go much to the chagrin of Chief Inspector Shiba Daizo, who distrusts the Robot. Together they battle the crimes perpetrated by the renegade conglomerate R.R.K.K. “BADO” (Robot Rental Kabushiki Kaisha – Robot Rental Company)

The story starts off on a deserted island with a woman shouting "I ain't a chick!" while being chased by 100 male perverts in underwear!!!
Then it cuts back several hours earlier and we get to see how 'she' got into this situation.

It's a desperate struggle of survival on a deserted island between this woman and the different groups of men who are pitted against her, some of whom might turn out to be allies.

From Wikipedia :

Two years ago, a pair of idols, Tsubasa Kazanari and Kanade Amō, collectively known as ZweiWing, fought against an alien race known as Noise using armor known as Symphogear. To protect a girl named Hibiki Tachibana, who got severely wounded by the Noise, Kanade sacrificed herself. Two years later, as Tsubasa has fought the Noise alone, Hibiki ends up gaining the same power as Kanade.