From Mangahelper :

Humanity is on the brink of extinction as a flower known as “Viscar” infects humans and animals, turning them into mindless hosts that feed on others. If you get bitten by the infected, or inhale the pollen that emits from their bodies, the flower will plant itself into your brain. Humanity is fighting a losing battle against this world-wide pandemic, and most people have given up hope.

Volt was once part of the army and had been assigned to be the guard of Dr. Kisling, the scientist leading the development of a vaccine to fight against the Viscar. From an unfortunate accident, one of the contained Viscar pollen escaped, infecting Dr. Kisling. Dr. Kisling’s final wish to Volt was to find his daughter Lilith, and, with her help, continue the development of the vaccine. Lilith and Volt now venture into the post-apocalyptic world to bring back hope to humanity.

The lead character, Jimmy (Katsuya Oonishi) is an art student at Bara-Gaku ('Bara Juuji Gakuin'; Rose-Cross Academy). When he was little, he almost drowned, but was saved by a tattoo artist. From that day, Jimmy vowed to become a tattoo artist (because tattoos signify 'a hero' to him).

Jimmy's a decent person by nature, but because of the people he hangs out with, he's considered a delinquent. Banko, his partner-in-crime, is a shrewed kid; he sells information on the popular girls (phone numbers, likes and dislikes, etc) in the area. Despite the delinquent exterior, Banko is actually really smart and has broad general knowledge.

As the story progresses, Jimmy and Banko meet new people and they form a gang of their own; along the way they bump heads with other gangs from other schools/districts. This manga is not the typical highschool-slice-of-life story; it's got a rougher edge! This manga depicts some high school delinquents trying to get through high school life and gang fights. Okay no, mostly just gang fights.

Chuuta Kokonose is an orphan who lives with his aunt. For as long as he can remember he's had a voice in his head, but other than that he's been a normal boy—right until the day when a strange thing follows him home and teleports him to a place filled with even more fantastic creatures. It's a police station in space.

Surprisingly, Rein Brickke, the Chief of the Solar System Department, tells him that their computer chose him as a potential candidate for the solar-system's police force. However, Misuzu Sonokata, a girl from Chuuta's school with an angelic face and ill temper who turns out to be one of Rein Brickke's subordinates, doesn't think Chuuta is suitable for such a job.

Although Chuuta was shocked at first, he decides to take the aptitude test after being urged by the voice in his head. Most importantly, he wants to prove Misuzu wrong.

Prequel leading to the events of 009 Re: Cyborg, after the end of the Cold War each of the zero zero number cyborgs go their separate ways.

The adventures of Marciel and his dragons continues. In Koryuu Monogatari, the baby dragons have grown up a little.

What kind of fetish do you have? A comedy about a collection of rascals and their embarrassing club activities!

The 1998 official Xenogears 4koma manga.

In a chance moment, the yakuza Takeomi happens to save a young man being attacked, who turns out to be the son of the kumichou, Seiya. Since men keep coming after him, charmed by his ethereal beauty, the kumichou had forced Seiya to stay locked away. Ever since that day, Seiya has become Takeomi’s responsibility. At the same time, the sudden death of the kumichou leaves Seiya to take up the job in his place?!

1-2+extra) Narushima, an elite detective of the Metropolitan Police Department who is guarding an important person at football stadium happens to meet his old friend, Fujisaki. When they were promising football players in same team, Fujisaki always dominated Narushima and deprived all of Narushima including of his pride and girlfriend. But Narushima realizes that Fujisaki becomes a sniper. He failed to catch Fujisaki and Fujisaki also failed to kill the VIP. They meet again and make love together...

3) An ex-member of swimming club encourages a retired member by fatal injury to tell the ace swimmer his feeling. Ace swimmer accepts it because he loves injured butterflies...

4) A teacher tries to find out the reason why his student acts rebelliously only against him...

Volume 1:
Seto Atsushi, the student council president, is tired of spending his days in the student council where there’s nothing but boys, and decides to recruit new members, but on one condition: they must be girls! Then Ozawa Kanae, a former delinquent, shows up in the screening for the secretary position carrying a bamboo sword…?! This is a collection of five related oneshots with a specially drawn short extra, "Classified!! Student Council Report!!"

Content:
Ch.1 Seishun Trickers
Ch.2 Seishun Trickers ~Newspaper Club's Komatsu-san~
Ch.3 Clear Sky
Ch.4 Brandnew Days
Extra 4.5 Classified!! Student Council Report!!
—Freewheeling Scanlations

Volume 2:
Komatsu Akina is a passionate photographer for her school’s newspaper club. When Aoi-kun of the Student Council confesses to her, all of a sudden she has this huge decision to make. Since she has never dated before, Komatsu is confused as to whether or not she should date the extremely popular Aoi-kun, who is constantly surrounded by pretty girls.
—Dazzling Scans

Spin-off:
Sakashita-senpai no Koigokoro

From a school story of a kouhai being fooled by his ill-mannered senpai, to vampires and time travel, the vast, heart-clinching world of Kashio is jam-packed into this book!

1. Chronic

2-3. Haru e no Tobira

4. Sawaranaide, Kowareteimasu.
After acting up in Soccer Club, Saitani is forced to resign and his teacher suggests he join the Astronomy Club. There, it’s just him and the supposedly sleazy upperclassman, Tajima. Although Tajima is very unmotivated and likes to order his kouhai around, Saitanai feels drawn to his innocence. But someone who knows Tajima tells Saitani that he loves men.

From MangaHelpers:
After his father died, Naruse Akira retreated into video games, and his mother retreated into alcohol. Naruse plays games almost all the time, getting him in trouble at his private school and worrying his childhood friend Hoju. He's incredibly good at war games because he is good at reading his opponents.
One day, he ends up downloading a strange game called "Revolt" onto his phone. It's a game that has him orchestrate a revolution, and the graphics seem incredibly life-like. At the end, he learns that he was actually giving real-world orders, and that the game was part of a scouting process for a company that helps to run revolutions. Now they want him to be their commander and help them save the world.

A collection of stories:

1. Rakuen no Jouken (The Conditions for Paradise)
Two adult women figuring out the boundaries in their relationship--is too much freedom a bad thing?

2. Hoshi no Mukougawa (Beyond the Stars)
Chapter 1 prequel. It's about how Sarina and Sumi first became more than friends.

3. Bathed in Sunlight Filtering Through the Trees
A continuation of Sarina and Sumi's relationship.

4. 20 Musume x 30 Otome
About an art prep school teacher who feels like she can't compare to her new 20-year-old girlfriend.

5. The Opposite of "Seme" Is "Protector"
Chapter 4 sequel. Keiko wants to take things further. There are two more stories in this series in the Lapis Lazuli Dream collection.

6. We're Aiming for Love Now
It's about two women who love each other just as they are.

7. Momo no Aji (Peach Taste)
A girl struggles to convince the object of her affections to take her seriously.

8. Sakurahime Hanafubuki
Set in Japan's past. A knight protects her princess.

Kai loves his stepbrother Riku from the bottom of his heart. However, Riku treasures “the bonds of siblinghood” more than anything, so Kai must hide his feelings and instead act as a “good brother”… but skinship no longer satisfies him anymore!

From Garo 1992-01.

Laura was abandoned in the forest as a baby and raised by wolves.

From Garo 1982-07.

From Aerandria Scans:

Venice, the latter half of the 16th century. Young Legare works as an apprentice to his father, an apothecary, but his real passion is the forbidden art of Alchemy. One day, a fortune teller predicts that he will meet four people with the power to change destiny and shortly after, his father is incarcerated on suspicion of alchemy. Legare, the real alchemist, is forced to produce gold for the person who arrested his father. Follow him through the mysteries of Venice, through his struggles, his encounters with powerful friends and enemies, and his search for the Philosopher's Stone.

A collection of oneshots.

1) Hen Ai: A oneshot that describes the "strange love" the two main characters share. Rather humorous, as it often brings up that one is rather adamant about wanting to roleplay and the other "grudgingly" goes along with it.

2) Tomari Ki (Torch): A man is stabbed and left for dead in an alley, but he is saved by a young man who has a halo and wings who calls for an ambulance. Later, the boy appears at the man's front door and claims to be an angel with broken wings, and states that the only way for them to heal is to make people happy.

3) Messiah no Yakubi (Messiah's Bad Day): A man known as the Messiah whose tongue technique is said to heal impotence takes up a job to heal a nervous-looking man, but is quite surprised by the turnout.

4) Ore no Doukyuusei ga Binkan Sugite Yabai!: A pair of high schoolers decide to experiment by giving each other blowjobs. One wants to escalate to something more, but the other isn't sure...

5) Ore no Doukyuusei ga Kagen wo Shiranakute Tsurai: Continuation of the previous story. It escalates.

6) Kyoushitsu no Yugami: A oneshot regarding the "relationship" between a teacher and his lonely, introverted student. (sequel to Yugami Hajime from the manga Yajirushi)