From ADV:

When popular high school student Chiko finds a cell phone, the voice on the other end tells her where she can witness a suicide! The phone doesn't stop ringing, and soon Chiko and her classmate Bando will have to race against time to save these lost souls.

From Tokyopop:

Gun has always been a problem kid, but after a tearful plea from his mom, he decides to turn over a new leaf. Vowing to abandon fighting and troublemaking, Gun transfers to a new high school, attempts to be a good student, and rents a room at the local coed dorm. There he falls for Seung-Ah, the dorm owner's granddaughter.
However love is not to be for this couple, as sexy Ji-Ae's untimely advances always thwart his attempts to woo the innocent Seung-Ah.

Aoyama Keita had a crush on his classmate Haida Monako, but he was too shy to tell her. One day, when Haida suddenly passes away, he is finally able to confess to her through a letter he places at her funeral. Little does Keita know, she returns as a zombie and blackmails him into letting her stay with him with the threat that she will tell everyone about the love letter if he doesn't. Now Keita has to hide Haida from his parents, classmates and the outside world because everyone else thinks she is dead. To make matters worse, as a living dead, she craves flesh from time to time and Haida doesn’t care if it comes from Keita…

Yoshotoshi Heion was a 1st year high school student who had no desire to excel--and liked it that way. In fact he chose Hiyotani High school for that reason. It was an average school only 5 minutes from his house. There's even a cute girl in his class, Rina Fujimoto, and he's already given up on her. But Rina wants to join the "Wind Orchestra Club" (Brass Band Club) only to learn it's been disbanded. Rina's passion for music inspires Yoshotoshi to help revive the club. "Once you make the first step... Who knows what will happen?"

Hayate's father, Tani no Maju (another loyal "Chiguruma Tou" clansman) had discovered and developed the "Ninja Henshin Jitsu" (Ninja Transforming Magic/Techniques) that enabled man to transform into super powerful "Keshin Ninjas" (Spiritual Ninjas) who would be able to summon and utilize their own inner mystical powers. Majin Sai wanted to use this technique to further "Chiguruma Tou's" cause and make their warriors invincible. Tani no Maju resisted handing Majin Sai the secrets to this technique believing that in the wrong hands, this technique could pose a monumental threat to Japan. Majin Sai sent one of his "Youkai Ninjas" (Supernatural Ninjas) to steal the secrets of this technique. In the process Tani no Maju was killed, but not before he had shown Hayate the secrets of this process. Enraged, Hayate uses these techniques to tap into his inner mystical powers and becomes the super powered ninja "Arashi" (Storm).

On August 10 of 2019, humanity received a signal, which was verified for its integrity by hundreds of scientists, from an alien life form containing one message: let us meet on Mars on July 7, 2035. Thus began the creation of a space agency representing Earth as a whole named ST&RS. From there, things progressed quickly with man re-landing on the moon in 2022 and constructing many space stations orbiting Earth and the moon. The Space Academy was created to train the upcoming generation of ST&RS.

The same August 10th that Earth received the message, Shirafune Maho spoke his first words and it was “Mars.” Since then, Maho has been an astronomy freak who has nothing but the universe on his mind. He decides he is going to apply for the Space Academy along with his childhood friend, Hoshihara Meguru, and recent transfer and super smart classmate, Amachi Wataru. The trio begins their almost impossible journey of being accepted into the school where only 1% of the applicants are allowed into the academy.

A mystery guy who failed every exam has now awakened!! What would this guy do to make world change?!!!

13 years ago, an unknown object appeared at Shinjuku. That creature regularly gives birth to a demon. Therefore, our world is being eaten clean.
The military found a weapon capable of fighting these creatures, a special power known as "exex" that becomes part of the human body.

From MangaHelpers:
Minami Eita lives with his older, book-loving brother, whose long-time girlfriend Arumi is often around the house. Minami tries to get along with Arumi, but the truth is that he likes her much more than is appropriate. Even though Minami doesn't read much, he helps in the library with his bookworm classmate Shinonome Yuuko, who loves short stories. She thinks that while most people want to think of themselves as the hero of an epic saga, short stories are much more like their actual lives. Minami's ordinary life becomes more confusing when he begins to suspect that he has feelings for Yuuko. One day, he finds out her secret--she is actually a published author of short stories! Her publisher wants her to write a novel, and she has enlisted Minami's help in an unexpected way. Minami's teenage life is not going to get simpler anytime soon.

Follow the adventures of our sexy redhead zombie-hunting badass heroine!

A powerful sorceress, Felicia Rand Philistin, once tried to conquer the nation of Shurian. In her wake of terror and destruction, a single man stood up and rebelled against her oppression and domination. The people called him Maian the Brave (Yongja Maian) and it was he that sealed the evil sorceress.
A thousand years later, Fenix Maian in a strange twist of fate releases the sealed sorceress that his ancestors have tried so hard to keep imprisoned. Now he has to keep the sorceress from taking over the world once again...

Kotarou Hayasaka is a new student at Oomiya High School, a prestigious boys school where the student council president is able to make a single school rule at the beginning of the year. This year, the student council president Izuki Jinguuji decides that all the students have to cross-dress during school activities, much to Kotarou's dismay.

From MangaHelpers:

In ancient Japan, the Shogun established the Ooku, a harem of beautiful females, to give birth to and raise the heir to the throne. But 400 years later in a timeline slightly different from ours where the military empire still exists and Japan is still closed off from the rest of the world, the Ooku is in chaos. What used to be full of gracious and refined ladies, the girls now are violent and rude. They do as they please, get themselves into shenanigans and wreck havoc around the castle! [vyc]

In the Kidou Senshi Gundam-san series:
1. Saisho no Maki
2. Tsuki no Maki
3. Mittsume no Maki
4. Yottsume no Maki
5. Itsutsume no Maki
6. Muttsume no Maki
7. Nanatsume no Maki
8. Yattsume no Maki
9. Koko no Tsume no Maki

From MangaHelpers:

In 2019, childhood friends Yashio Kaito and Senomiya Akiho are in their last year of high school. Together, they are the only students in the robotics club, which has lost its school funding. Akiho is passionate about robots, and longs to complete building the robot her older sister Misaki began in this same club. Kaito doesn't really care about robots, and is obsessed with video games, specifically "Kill Ballad Online." However, he stays in the robotics club due to his friendship with Akiho. Now, just after Kaito is accused of cheating in his favorite game, Akiho decides to risk her club's existence in exchange for the funding to finally finish her sister's giant robot... [tethysdust]

From The Zero Alliance:

Wisdom brings good fortune; but wisdom that is too advanced to humans bring destruction.

Ox and Ivan, a pair of “wisemen”, are on a journey to collect wisdoms that are in the wrong hands.

Official anthology by various artists, based on Daily Lives of Highschool Boys.

Ookuni Kenichi is the successor of the Inaba Shine. After 10 years away, Kenichi returns to the shine to follow in his grandfather's footsteps. After misunderstandings and mishaps, Kenichi discovers the four shrine maiden's secret and wonders which one is his childhood friend that he made a promise to.

In a world where every land strives for power, two Wakis named Chado and Poky, traveling aboard a flying boat, accidentally land on a very dangerous island. Prepare yourself for an epic journey into a huge universe!