This series is the reboot to the original Weekly Shonen Jump series Juuki Ningen Jumbor. This manga takes place in an alternate universe from the original story, but features many of the same characters.
(Source: M-U)

"You" once again escaped from the prison to a high school where he became a transferred student. Now what kind of lesson was he going to teach his "classmates"?
This is a direct sequel of Hammer Session and is placed 6 months after the original series.
(Source: MU)

One day while Shirou is delivering a secret device to his colleague, he meets Amane Mao, a super-strong girl capable of lifting cars. This device, the VITA system, is a new weapon theoretically capable of defeating ERRORs: a breed of enormous, cybernetic mutants that necessitated the use of weapons of mass destruction on Old Tokyo fourteen years ago.
Suddenly, one such ERROR appears before the two and goes on a rampage. Shortly after a failed argument to convince his colleague to approve use of the VITA system simply to save civilians, his colleague is devoured by the ERROR. Faced with death, Shirou has no choice but to accede to Mao's request to activate the super-weapon and destroy the ERROR.
...and thus Shirou's eventful days as the male master of the VITA system at St. Liddel's Girls' Academy are about to begin...
(Source: Edited from AnimeSigma)

This 4-koma style manga features Yoshiko, a genuinely stupid girl (she can even manage to get all 0's on multiple choice tests). She hangs out at school with her childhood friend, who she claims to like, and he has to put up with all her ridiculous behavior!
(Source: MangaHelpers)

Binta Yugawara is a "Bodz" or Bomber Kid, in the city of Atamu, who dreams of defeating his hero, Smash Kintaro. While in the city, he battles using a pog like game system, against several other Bodz, including Banji Chihara, BJ, and a man by the code name, "X."
Hiroyuki Takei (of Shaman King fame), is the supervisor for this series. All artwork is officially drawn by Kato Gaito, who later helped assist Takei with "Jyuki Ningen Jumbor." The series was canceled after 3 chapters and never met the intended 197 pages announced in the first chapter. Neither Shueisha nor Takei have ever officially mentioned this series since it was canceled.

After dating for half a year, Masaaki decides to take his relationship with his mature senpai to another level. He gathers up his courage and tells her his thoughts right before Christmas Eve.

How will senpai react?

Yuuichi Tate is overjoyed: He gets to go to a brand new high school. Of course, then he just happens to find out the school he choose is under frequent attack by strange creatures called ''Orphans'', and the school set up a special task force of female members called ''HiME''s, using various elements as their powers, to battle these invaders. That's not all, though. Each member of the HiME task force has their own, unique ''Key'', another person whom, upon being discovered, can team up with the HiME to create a ''Child'', a combative unit specifically needed to effectively battle these Orphans. And with Yuuichi's luck, he just happens to find out he's not just the ''Key'' for one of the HiMEs, but for two... Two highly competitive, rival schoolgirls. And that's only the start of the trouble.
(Source: Tokyopop)

Short Story Based On The Long Running Video Game Series Of The Same Name.

Two beings, one of pure good and one of pure evil, infused with all the knowledge and abilities of their creator, were set to awaken when the world was about to enter its final war. Shortly after his masterpieces were completed, the creator committed suicide, satisfied with the potential mayhem his creations will cause. Now, 1000 years later, a peaceful city is terrorized by a monster attack. The monster was created by the "pure evil" being named Vice, as a means to draw out his "pure good" counterpart, Ultimo. When the monster starts wrecking the city and attacking innocent bystanders, Ultimo appears to take out the monster. Finally, the two meet and their grand battle begins. Who will win? Who will lose? What do the police think about these new creatures destroying their city?
(Source: MangaHelpers)

A sequel to Mai Otome,which introduces Archduke Nagi's younger sister. Who is disguised as a man. Arashi (Nagi's sister) has bought Garderobe and all of its properties. The story starts from there.