From MangaHelpers:
Humanity has found the perfect energy source that gives the wielder near god-like powers. This energy source has been named "Demon". The rare individuals that have the capabilities to wield this power are known as "Mediums". To become one of the Mediums, Taichi has transferred to the Meissner School. On the first day of transferring into the school, he literally runs into an energetic girl named Nui. She is a Medium and attends the Meissner School. Taichi will require her help to become a Medium himself and survive against hostile Mediums.

Utsutsu and Yume Hasegawa have been living all on their own. One day, Yume sees red butterflies and something strange happens to her body!! As the siblings are toyed with by “Pupa,” so begins their tale of heroic love... (From JManga)

This is a tale about a floating continent . 6 years ago , a disastrous monster attack marked the beginning of mankind's extinction . This is a story of the remaining survivors who struggle to fight and learn about these mysterious monsters as they prepare for a great counter attack . Will they succeed and regain their rightful rule of the continent? Or perish before these monsters.

From Viz:
140 years ago in Kyoto, with the coming of the American "Black Ships," there arose a warrior who, felling men with his bloodstained blade, gained the name Hitokiri, man slayer! His killer blade helped close the turbulent Bakumatsu era and slashed open the progressive age known as Meiji . Then he vanished, and with the flow of years, became legend.
Ten years later, a young woman's life is saved when she happens upon a strange wandering swordsman named Kenshin. The young woman accepts the wanderer into her dojo, despite his secretive past, and the two become fast friends. As their relationship grows, they meet and make more friends (as well as enemies), and they grow accustomed to their life together.
However, one man can only run from his past for so long, and it isn't long before Kenshin is forced to face the life he thought he'd left behind. Now, together with his friends, he must fight the ghosts of his past if he wants the people he loves to have any kind of future.

Contains a side story called Yahiko no Sakabato.

The protagonist, Houkou Hayao decides to take a job interview at a family resto, Berry's, in order finds out what to do when he graduates.

On the same day as the interview, he bumps into a certain "ojou" who just got out from the interview room in a bad mood, and binge eats at Berry's. He later ended up hanging around with her. When he gets home, he finds out that Yuuka, his "imouto," has found out that he got a job without her permission.

Later, he learns that the binge-eating girl which introduces herself as Morikubo Yuna he met is a new employee like him.

Each of this manga's chapters features a new girl. The first chapter starts out with Ichikawa, who mysteriously has a shounen manga show up on her torso each week, a malady she shares with her male classmate, manga-fan Aoi. The second girl, Kawamura, notices that a boy in her class is suddenly being duplicated!

A princess who holds a piece of a legendary treasure map known as the "Stone of the Sea" willingly joins a famous pirate in order to avoid becoming the twelveth wife of some 72 year old king...

(~from manga-mania)

From Tokyopop: The One Year War between the Earth Federation and the Principality of Zeon has begun--and the newest Mobile Suits are tested for battle! Captain Matt Healy leads his team into dangerous territory as the leader of a Special Forces Experimental Unit. Ken Bederstadt is a Foreign Legion Lieutenant working in alliance with Zeon. These two heroes are trying to keep everyone alive...for tomorrow! There are 2 editions of this manga, the 2003 edition (same as Tokyopop version) and 2005 "complete" edition with 2 additional chapters - a prequel and a conclusion to the storyline

From: Easy Going Scans

Luca Athrason has been sentenced in 500 years of imprisonment – such is the price to pay for his sins. The only way for him to shorten his sentence is to accomplish his missions as the Church’s vanguard or as some might call it... The Church's Dog!

Enslaved Ninja are forced to compete in the Arena and fight until death!The victor is given the chance to progress until they defeat the current champion. If they succeed, the winner will be rewarded greatly and granted freedom.

To celebrate Weekly Shonen Magazine's 50th anniversary, Hoshino Yasushi drew a one-shot version of Cyborg 009 dealing with how Joe Shimamura first became a cyborg and how he met his comrades.

During a long drought, a runaway boy comes across a flying mountain, carried around by a gigantic turtle that only he can see or hear.

From MangaHelpers:

Yuta is a normal high school boy living in a normal house with his parents, but his cat turned into a beautiful girl. His parents believe that the cat-turned-girl is a god that will bring great fortune to the family. Yuta has now been forced by his parents to marry his cat. Will Yuta be able to accept the fact that his future wife used to be a cat?

Being referred to as a " witch hunt ", the act of torturing and killing innocent girls allows the devil to bring them back as witches. Domino Archcarlo, the "Inquisition Witch", was sent from the church to stop the creation of new witches. Domino's battle begins!

Sequel to Nozo X Kimi. In their second semester of high school, Nozomi and Kimio are in the same class again, still on their quest to help their schoolmates face their own private true-self. Nozo X Kimi migrated from Shonen Sunday S to the much more popular Weekly Shonen Sunday but, instead of being continued from where the previous serialization ended, a second season was started.

This world is full of weird things. Each of them is a knot. And I am the one who will untie all of them, until I found the "key"- the key can save me from this world.Note: Read left to right

The world as we know it was suddenly altered forever when the door for the dimension of the gods and the door of the dimension of the demons suddenly opened up. Ten years later, a boy named Tsuchimi Rin was entrusted with two princesses from those dimensions. Will he be able to keep his sanity while living with his childhood friend Kaede, trying to live a normal school life, and also being a neighbor to both of princesses and their fathers, the mighty dimension Lords? The hearts of those girls are at stake and only Rin has the key to unlock them.

Group of soldiers fighting against aliens after the conquest of the planet Earth.

*It should be noted that the webcomic was originally published on Naver, but that version has now been canceled. The author started a new version on TTale which is the one currently being translated by Webtoons Reader.

In the town with a lighthouse, Inuhouzaki, the police patrol division's new recruit, Kurumi, and the talking middle-aged police-car-dog No.1 are on the case. Everyday, they somewhat protect the peace of Inuhouzaki, but is it okay to leave it up to the rambunctious duo. The new sensation that is the cute, slice-of-life short comedy is here.