Gag manga. Based from Dangan Island scenario, an IF scenario where no murders happened. Full of comedy… Black comedy.

“There are three murderers hiding in your midst.” These are the ominous words given to the six survivors of a tragic bus accident, followed by an ultimatum: Within one week, the murderers must anguish over their crimes and find some way to answer for them, or the evidence of their sins will be given to the police. But when every person has a secret, who can you trust…?

Based on the original work by Eiji Nonaka, Cromartie High School: Staff Room is illustrated by Ichiban Ino and follows Tatsuya Aoyagi, a tough teacher who transfers to Cromartie High School with the intent of pounding some learning into the students' heads.

A 4-koma manga that re-imagines the anime's title character Lelouch Lamperouge as a part-time convenience store worker.

From The Company: Prophesied death. Boy who challenges fate. The fight against the world's fate itself begins now. Original webcomic

Black Jack is a genius surgeon who never acquired his license due to his clashes with the medical establishment. He is hired out by anyone willing to pay his exorbitant rates and is perceived as a heartless rogue because of his enigmatic nature and antisocial manner but that is not the whole story.

Note: 8 previously-sealed chapters were republished and were never officially nor unofficially translated.
Won the 1st Kodansha Manga Award in the Shounen category in 1977 which was tied with Mitsume ga Tooru.

Aki's adopted father has been gruesomely murdered, and Aki herself is the main suspect! With nowhere else to turn, Aki must depend on the mysterious Anato Misuto to clear her name.

This manga follows Gourai, a newly activated Frame Arms Girl at Factory Advance as a test for self aware AI along side several other FA Girls.

Sukami Kyouichi was born into an exorcist family, and his older sister is an expert exorcist. She's been putting together a notebook where she has written how to handle all of the different monsters she's met in her work. One day, Kyouichi and his friends in the Occult Club at school go to investigate a supposedly cursed shrine, and he ends up needing to be rescued by his sister. Shortly afterward, she goes missing, presumed by many to be dead, and leaves her little brother with only the notebook.

Kyouichi stays in the Occult club, and as he grows up, he remains dedicated to the search for his beloved older sister. One day, his search starts to finally make some progress, when a shinigami who claims she was his sister's friend appears...

Jubei lives for adventure. When he is hired by a mysterious woman to retrieve a mystical food that grants eternal youth, he thinks it's a simple job—until he finds out the secret of the special ingredient...

Despite his constant anemia, an accident leaves Akagawa Touma infested with an alien blood parasite, and the unintentional protector of Earth.

From Game of Scanlation:

Park Chang-hyun had to move and move again because of his father's business.For the first time in 8 years, he's returned to the village where he grew up young. On the first day of his highschool a certain beautiful young girl catches his eyes. Her name is Yang Surh Hee. She currently reigns as the school's idol but in the past they both went to the same school. Before his transfer he had a big fight with Surh-hee but their reunion went smoothly and he returns home... to find Yang Surh Hee!?!?!? "Yang Surh Hee is my house maid?!" "If you tell this to the school I won't forgive you, Park Chang Hyun!"

500 years ago, the Monkey King invaded the heavens in search of more power. Fearing for the worst, the Emperor of the heavens summoned the Buddha himself to restrain the Monkey. Buddha recruited the 5 most powerful monks on earth. They separated the Monkey King in body and soul and imprisoned him. Today, after 5 centuries, these Monks continue to exist recruiting and training monks to succeed them and keep the heavens and the earth safe. Onk is a young man of thirteen who dreams of joining the temple of the 5 monks and becoming a Dragon Master to help his humble village, so he must overcome the most improbable and complicated challenges of that journey.

Natsuki Nanahoshi is a junior high school student with an unlikely secret who is scouted by a… stuffed animal? This… thing tells Natsuki that keeping his secret for so long has given him magical powers, and then forces him to become a Magical Boy!

Enjoy this “forbidden” magic fantasy filled with sorcery, boys, and kissing!

A game programmer with a special skill....

From Tokyopop:
In a school where martial arts are standard curriculum and disputes are settled by officially recognized duels, Ryoko takes on all comers. As the #1 fighter at Daimon High, Ryoko's battles to defend her position never end and "Finals" take on a whole new meaning.

From ADV:

Sosuke has finally lost his mind - and his memory! Rehashing his previous exploits will keep Kaname busy, but it doesn't take long for the military mind of this soldier to bounce back with a bang - literally! He's locked, loaded, and back to his old self by first period, as bombs and bullets grace the halls of high school!

A sudden transmigration cycle occurred, breaking the norms of a normal high school student, from that day onward, he enjoy the company of otherworlders but how he adapts to the comedic and absurd lifestyle when the impending threat of the world looms near...

Even with the process being an exchange and not giveaway, innocence once lost can never be restored.

Or something.