From Shinnen:

There are rumors of a grand treasure located within the local museum of Ashiwara and that this treasure requires a special key to unlock. But no one seems to know what this treasure is or even what the key looks like.

But Kei and Hikaru, two childhood friends, may inadvertently find out when someone seeks to claim the treasure for themselves and that action plunges their world into chaos.

From Manga Jouhou:
Takashi Sone is living on his own while he is attending college. Out of the blue, his parents tell him that his sister, Mafuyu, is moving in to live with him and that she will be attending a high school in his area.
When she arrives, he finds out that she was kicked out of her old school for getting caught making out with another girl. Soon afterwards, the other girl arrives, having thrown away everything she owns in order to run away and live with Mafuyu.

Volume 11 has a unreleated 2 chapter story at the end called Frills

Watanabe, an alien student from 20,000 light-years away, comes to homestay with the Tokino family to gather material for his thesis on Earthling behaviour. He follows around the various family members asking mostly funny but sometimes profound questions about their work, their loves, their polluted air... When he's not being sent on errands or punched in the face, at least.

Yoshiaki is entering a school that is famous for its fights and violence. He chose to go there for just that reason, and he intends to be the strongest one there. When he first arrives, he helps out a girl called Homura, who is being picked on by some guys. When she asks him to be her "sword" afterward, Yoshiaki doesn't know how to respond. Apparently, students of the school team up in pairs; a "sword" and a "master". Others advise him not to associate with the girl, who is a "Rank F", as she probably won't live very long. However, Yoshiake is not thrilled with the idea of abandoning her to die.

The year is 2008, and Mikuru is a 16-year-old high schooler who often disagrees with her mother Yuki. One day a girl appears in front of her with toughts, memories and body are from 24 years earlier. In short, Yuki has time-slipped from 1984 to the present, and when Yuki wakes up she is shocked to find that the year is not 1984, and that Mikuru is her daughter.

Now both mother and daughter are the same age and living in the same house together, with an older man who is supposed to be her husband. Until when she can return home, the girl who has crossed space-time decides to discover her future.

On a trip to look for his brother, a hungry Hachiya Rei stops at a shrine to pray. It is just his luck that he is accused of stealing money from the shrine and forced to work to pay off the amount stolen. However, the real thief turns out to be a daemon, or a god turned evil! An encounter with the daemon unleashes Kagutsuchi, the god of fire, concealed in Rei. As Kagutsuchi's proxy, Rei can use the god's holy fire to purify daemons, but there's a side effect...

Only the strongest woman is worthy of being Queen. On this continent, a desperate struggle to crown the new Queen is held every four years. The Queen's Blade.

Lucius Lucent is a cold blooded female warrior that makes men in battlefields quiver in fear. Along with her magical armor, Gil, she destroys everything in her path with her overwhelming power.

In a city split between humans and occult, Colin Aston just wants to run his diner and make bad coffee. A peaceful life isn't on the menu though, as a mysterious blonde shows up with a job only Colin is capable of performing. If he takes it, Colin will have to face sorcerers, politicians, and little old ladies... not to mention a secret that destroyed nearly half the city and hits a little too close to home.

Explore the lives of the famous-yet-not-so-famous people of history; such as Nikola Tesla, Ty Cobb, Typhoid Mary, the woman behind the Winchester Mystery House, Kou Yoshio, and many more.

Series of one-shots published between 1989-2003, released a tanko volume in 2004 and a bunko release in 2012.

From Brolen:

This is a horror/sci-fi story about a giant planet consuming creature from another dimension that a scientist discovers and mistakenly identifies as a planet. Being given the honor to name it as its discover, the professor chooses to name it after his only daughter, Remina, but when Hellstar Remina is headed on a direct collision course with Earth the world goes nuts and all the people in the city start a witch hunt to kill Remina, thinking she is somehow to blame.

Hellsing, an organization devoted to the elimination of the vampire threat, has recently uncovered information regarding the attempted production of "man-made" undead. The world is presently in the thick of WWII, and the current leader of Hellsing fears the Nazis could potentially use these creatures as front-line super-soldiers. Although the technology of creating artificial vampires is still in its infancy, it has advanced enough to be a serious threat. In an attempt to put a stop to this perverse and dangerous experimentation, Hellsing has sent two of its most skillful agents to Poland. A young man by the name of Walter C. Dornes - a.k.a. "The Angel of Death," and Alucard, an ancient vampire currently in forced service to the Hellsing Organization. Together, they attempt to stop the progress of the Nazi's efforts.

From MangaScreener:
A professional baseball manga by Harold Sakuishi, the author of Beck.

Taiko Busujima is a powerful young pitcher looking to make it into the Japanese big leagues, but what he didn't count on was being signed to the Keihin Athletics, the cheapest and worst team in the league. Can he help turn the Athletics around and (gasp) win the pennant?

A gripping, edge-of-your-seat story loaded with Sakuishi's brand of wacky humor.

Flowers and guns...
With a gun in their hands, the girls will seize their days.

Himawari! is the story of Himawari and her journey to become a Kunoichi, and her 'vow' to protect her master.Himawari Hinata recently transferred to Shinobi Gakuen to train to become the best kunoichi she can be. She wanted to be a ninja ever since she was saved by one when she was little. On her first day, she meets Hayato Madenokoji (a new transfer teacher) who saves her life. Hayato does not possess any ninja skills or traits, he is teaching the ninjas about normal society to pay off his debt. However, Himawari notices that Hayato bares the same mark on his neck as the ninja who saved her when she was young.

Sequel to the first anime series and a prequel to the second anime series.

Enzo Takaya, character inspired by Jean Reno, is a teacher and the oldest son of his family, as such, he takes care of his siblings like a father. One day, a 5 year-old girl is found on their doorstep with a note: she is the result of Enzo's former life of crime and luxury as a gang member. Although he ignores who the mother is, he decides to take in the little Nanami. She unfortunately suffers from a skin disease due to sensitivity to pollution and certain types of food. So, Enzo becomes a health freak...

Hama Rinko is the head of the school cafeteria while Konishi Shino is her helper. The two garner the attention as they provide eye candy for the student body and their stomachs. This 4-koma explores the interaction between these two young ladies and the student body.

A girl finds a strange tiny man riding a bee.

This is the story of Yuria, a woman with the power to foresee the future, and destined to re-unite and rule over a war-plagued land. Along with the her companion Kenshiro, she struggles to comprehend the depth of her power, and to defy fate to save the ones she loves.

A oneshot story about Kenshiro's sifu Ryuken and also the other adoptive brothers. Elaborates on how he chose the Hokuto Shinken successor and the events related to it.