In the hopes of pleasing his childhood friend and crush, Chiharu, Arata agreed to help her clean out an old warehouse from her grandfather. But what neither of them knew was that the warehouse contained "tsukumogami", ancient objects imbued with life. When Arata accidentally broke the seal on a box containing an artifact that hungered for vengeance against humanity, Chiharu was kidnapped! Now it is up to Arata and the good, loyal artifacts to rescue Chiharu before it is too late!

Minori is the manager of her high school's baseball club, which has been defunct up until five years ago. Even now, it's a little rough, since there currently are no seniors in the club at all! None of the second year players know why the club closed so many years ago, or about the baseball history all their fathers share...

The protagonist is your average, everyday, Korean school student. That is, if not for his obsession that aliens live on Earth disguised as humans.

Much to his surprise, he was right, the aliens play a game called "Avatar" where they take human form and live human lives. And because of a glitch he caused in their system, now his very life could be at risk.

Now he needs the protection of an Admin of the "Avatar game" or else he could very well die!

From Del Rey:

Since ancient days, the Gaius School of Witchcraft and Wizardry has trained the fiercest swordsmen and the most powerful wizards. Now one boy could become the greatest of them all. If he studies hard. If he is true to his friends. If he believes. And if he survives…

Another Amagami serialization in Comp Ace magazine. This version features Sakurai Rihoko as the main heroine.

N/A

A seminal history of Date Masamune. Yokoyama has a plain and matter of fact style for history without really trying to dramatize it.

This is an original story expanded from the STEINS;GATE game, and focusing on the heroine Amane Suzuha. In 2036, a monopoly on time machines has created world peace, but at the cost of human liberty.

Suzuha has followed in her late father's footsteps in fighting alongside the Valkyrie rebellion force to change the world. After the group fails on a major mission, Suzuha has almost no hope left. But then she discovers that her father left something for her: a time machine. Using this, maybe Suzuha will have the power to finally destroy this dystopian society and create a better present and future!

Sara Tanjuro just recently transferred to Mikagami Eruma's elementary school and have caused a major stir among the students. Tanjuro, knicknamed Satan, has been proposing his love to the girls left and right, something the shy Eruma would never think of doing. But Satan has a secret identity. He is a member of Michaela, a group of people who combine technology and exorcism to rid the world of angels that wreak havoc in society. As member number 666, Satan is an anti-angel specialist who has disguised the school supplies as weapons. He defeats supernatural beings with ease. Now if getting girls were that easy...

From MangaHelpers:

Natural selection has created a deadly new species known as "Eclipse," who are driven to eliminate humanity. A scientist called Kurusu Kenji headed an organization whose purpose was to fight these deadly creatures of bone. To this end, he created the "Osteon," Eclipse-like creatures that obey the commands of the human from whose DNA they are created. Now Kenji is gone, and his assistant Kidogawa Rokuko is attempting to recruit his estranged teenage son. Kurusu Akira wanted nothing to do with the father that he believed abandoned him, but attacks from Eclipse force him to accept his own Osteon from Rokuko. He slowly finds himself drawn into the organization, whose members expect him to take his father's place. Akira and his Osteon may have little interest in protecting humanity, but they are determined not to be beaten! [tethysdust]

Toshiki is a below average student and often the target of ridicule. After he accidentally runs into a shop sign and breaks it, he enters the shop and finds out it will sell him abilities.. But these abilities don't come cheap.

From Tokyopop:

Hack//4 Koma" is a four-panel (a.k.a. Yonkoma) manga series set in the popular multimedia world of .Hack. Most of the 4 Koma are filled with gags and parodies centering mostly around the main characters of the first (Kite, BlackRose, Helba, etc) and second (Haseo, Atoli, etc) series of ".Hack" videogame

From Lovers Dream: A high school boy and a female student spend the night in a hotel after drinking a little too much... ... without being able to remember what may have happened between the two of them! Three months later, the female student comes back to the young man telling him she might be...pregnant...?!

A soccer loving boy Takasugi Kazuya dreams of playing soccer with his Japan League star father at the National Yoyogi Stadium. The story follows Kazuya's life as he travels to Argentina, plays for Yamaki, and goes to the 1998 World Cup in France.

Satomi Azusa is a popular teenage gravure idol. She's also a highly talented baseball player, but, as a girl, she can't play on her school's team. Her father happens to be the coach of the team, and he concocts a scheme to allow her to play. His scheme involves Hirayama Keita, Azusa's childhood friend, a teenager of no particular talent. Keita's redeeming feature is that he looks a lot like Azusa. In fact, after putting Keita in a wig and girl's clothes, not even their parents can tell the two of them apart. To help Azusa's (and her father's) dream come true, Keita agrees to trade places with her during the baseball games. Soon "Hirayama Keita" becomes a popular player, and "he" begins to move towards a career in pro baseball. How long can Keita and Azusa keep up the act? What will happen when people find out?

Volume 1 also contains My Sweet Sunday.

Petey is a bounty hunter in a time and place full of bounty hunters. The criminals are outnumbered by the bounty hunters and whenever a wanted poster is posted, it doesn't stay up for long. Except for one... there's one wanted posted with a negative bounty and no one wants to catch this criminal. But Petey is curious and she seeks the help of a mystery solver...

Etou Kai may look like a squeaky-clean kid, but the Greater Kanto Narcotics Control Division's new investigator hides a violent alter ego and a dangerous past.

With his stoic partner Kurabayashi Hal, Kai is assigned to track down and stop the distribution of Dragon Speed, a dangerous new drug. But Ryuugen, the syndicate trafficking the drug, is almost impossible to infiltrate. Add street violence and a jurisdiction war with the Meguro Police into the mix, and it looks like Kai's in for some very long days at the office.

　Our protagonist, Inoue Konoha is still being led around by his senpai, the Literature Club's President, self-acclaimed "Literature Girl" who loves stories so much that she can eat them, Amano Touko.

　One day, someone put in the Literature Club's "Love Consultation Post Box" a bunch of paper scraps that have the words like "Hate", "Ghost is" and a bunch of puzzling numbers on them. Calling the act as "picking a fight with the Literature Club", Touko once again got Konoha involved in her investigation; but when they found the culprit, this girl turned toward them, smile, then said "I'm already dead."

　This is the second arc of the popular bitter & sweet school mystery series.

From Tokyopop:

Three years after the popular video game The World was shut down, Tokio Kuryuu cannot wait for The World R:X to come out. Unfortunately for him, he forgets to reserve a copy and finds himself with no access to the game. That is, until a mysterious new transfer student forces him into the game and makes him her servant.

G.U.+ follows the player Haseo, a powerful PKKer known as "The Terror of Death". Haseo is obsessed with an infamous PKer known only as "Tri-Edge" who attacked a close friend of his sometime in the past. The manga details Haseo's search for Tri-Edge, and his eventual inclusion in a mysterious group known as "G.U."


Back story of the ps2 game (same title)
In 2015 a fire at the main CC Corp. building resulted in the loss of a lot of data, and The World was forced to shut down. By splicing in data from what would have been another game, CC Corp was able to rebuild the game system. The next year, "The World R:2" was released, but many old players objected because they were unable to bring over their old characters. However, many new users were drawn in by the new style, and over 12 million copies were sold. Though not a match for the previous version's 20 million users, it became the top-selling netgame on the market." As a result of the new world, four major clans (Kestrel, Lunar Tree, Canard, and Raven) came to power. The clans actions shape 'The World', and most players end up taking one side or another during conflicts.