Hundreds of millions of years ago, highly-advanced beings looking to make a planet for themselves purposefully tampered with Earth's natural processes in order to create multi-cellular life. Watching the planet's evolution closely, they continued to help life evolve further in the hopes of having actual civilization develop.
It's now 1996 in Seoul, where Hyesong, a high-school student, struggles with the usual problems of youth. The only unusual thing about him is that he's been having the same apocalyptic nightmare for an entire month; in the dream he is an great fighter and genius tactician who faces off against a seemingly-unbeatable foe.
Are these dreams not really dreams? Does he really have a role to play in the cosmic balance of the universe? And is the new girl in his class really just a normal student?

From back of book:

He-Sung has dreams of the Earth being destroyed by alien invaders! In these dreams he is a motorcycle-riding warrior, the last defense against the alien armada. By his side is a beautiful armor-clad girl with strange powers and futuristic weaponry. But these are just dreams, and they don't mean anything... right? That's what He-Sung thought... until his mystery dream girl appeared as a new student in his school! But if she is real... can the aliens be far behind?

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…

The "Dark Flower" is a sword of legend; a horrible legend of a gruesome slaughter three hundred years past. Lilia, a small girl from a village threatened by the bandit group whose leader has obtained this cursed weapon is now searching for help to save her city. Unfortunately, she is spotted by the bandits and can only run for her life. But, just as she is about to be caught, she runs into a young and seemingly weak traveller... is this coincidence? The Winner of the 14th Square Enix Manga prize.

From Tokyopop:

Daphne in the Brilliant Blue take place in a near future in which the remaining population lives in underwater cities, with waterways as streets. Years ago, while conducting underwater experiments, all contact with the surface was cut off. With the remaining human population now living underwater, The Deep Sea 9 Cities Association represent the last hope of mankind. Ai Mayuzumi is the daughter of the head of the research lab, and is an expert water jet bike driver. When the terrorist group Error, attacks the city, Ai becomes involved with the counter-terrorist group Stelnas, comprised of an all-female team, and led by a girl named Kei, and asks to join them. The group initially resists her efforts to join, but a surprising "gift" that Ai possesses, along with the way she handles herself during a kidnapping attempt, eventually sways the opinion of the members of Stelnas.

The main protagonist is an Iga ninja named Saizou, who meets an Izumo priestess and protects her on her short journey to Sanada Yukimura. Sanada Yukimura is a powerful warlord in the Sengoku era. Sanada wants to gather 10 warriors, a party unrivaled in skill and power, to set his still secret plan into action.

From Iskultrip Scans

Yamada Hana, a high school girl, woke up and found herself in a strange land after being enveloped by a bright light that came out from a mysterious book. There, Hana met a young man named Gentoku, and ended up staying with him and his army as "Koumei's disciple"…

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.

.hack//Alcor takes place in the online game 'The World'. Nanase is a shy and naive girl belonging to the newbie helping guild 'Canard'. All she wants is to be with Silabus, the guild master whom she has deep admiration for. However, when the guild members are targeted by player killers (or PKs) from the guild Kestrel, will Nanase be able to brave the situation?

From Anime News Network:

A collection of short stories that look to mankind's exploration of space, and examine the possibilities that we could face when we decide to take those first fateful steps into the unknown.

From Manga Updates An ordinary high school girl, Lin Seonu, unknown even to herself is actually a woman saint holding ancient power called the "Jade of Bango." On her seventeenth birthday, she obtained the power to see ghosts, and every morning after that she goes to school accompanied by the harmless and lovely ghosts. One day, however, Lin has an abnormal dream, and that evening, she encounters a terrible evil spirit. Shivering in horror, she is rescued in the nick of time by a handsome man she had seen in a dream. He frees the ridiculous power that had been concealed in her. He says that his name is In Mu, and that he is her fiance.

"Lured by the sweet fragrance of the flowers which blanket the earth, with fangs of steel and claws of iron, to the Garden of Eden which welcomed the ages, under the guise of a disaster from the heavens... seven dragons appeared."

Based on the game with the same name.

Reika Ryuzaki, daughter of the late diamond collector Yoshio Ryuzaki, is a jewel specialist who fights with knuckles branded as "Krishna" in cases involving bad guys who rob or misuse jewels for their own gains. She has an advantage in fighting as she can summon spirits from certain jewels to aid Reika in making her a better combatant in the field.

From Ivyscan:

The Lord of Sanwa's son Lamkha saves Kanan, who collapsed on the road, and brings her home. In Sanwa, where the Messengers of Heaven or Flying Serpents roam the skies, a legend has been passed down the generations. According to the legend, a Holy Dragon fell from the heavens following a battle against a Black Dragon and was buried in Sanwa. What is the truth behind the legend?

Onodera Goushi is a high-schooler who isn't much noticed in other people's daily life. In a sense, his life feels like it would be the same if he wasn't around. Then one day while returning from school, he finds himself in a life and death situation where a strange girl named Honoka saves him by sending him to another world. He then gets sent to the "Demon Nation" where many non-humans live and where he is able to meet the Ma-Ou (Demon King) who is... an anime otaku?!?!

In 52 B.C., the Chieftain of the Arveni tribe, Vercingetorix, united the Gauls in a major revolt against the power of the Romans. This is his story, beginning with his rise to power. In one of the tribes, he rescues the 11-year-old Taranis, the only son of a Gallic hero who was executed by the Romans. Taranis follows Vercingetorix as he raises his army to fight for the freedom of Gaul.

The afterlife! Once someone goes in they can never make it out alive! Snow White journeyed to the spirit world with the pass to the spirit world her mom left her to find her dad's spirit but...

"To lose my love, or to kill her, those are the two choices I'm faced with."
The blood loving and cold, absolute devil, Pa Sun.

The one who wishes to protect Snow White’s happiness but must take her life, Tae San.
"I no longer have the right to be by your side, I love you.
Holding those feelings in my heart, I leave you for your sake."

Will our kind and lovely Snow White’s jealous sister Oori’s curse follow her to the afterlife…?

A small coincidence makes history!
The story of the earthlings and superhero Aimer's efforts to block an alien pumpkin gang invading earth is about to unfold!

The story of Garan, a travelling executioner who roams the land, killing bad guys.

There's 2 versions, one tankoubon and one bunkoban.

The tankoubon includes:
「暁に立つライオン」 - Akatsuki ni Tatsu Lion (published in Betsucomi, 05-07/2003)
「トルコ取材記」 - Turkey Shuzaizakki (Omake, 06/2003)

The bunkoban version also have the one-shots:
「海に墜ちるツバメ」 -Umi ni Ochiru tsubame
「記憶の足音」- Kioku no Ashioto
Both also present in Umi ni Ochiru Tsubame.

Resume from ShoujoMagic:
Izumi Erina is a senior in high school. She only has one living relative - her older brother Takashi. However, Erina receives an arrest notice for Takashi one day, who is supposed to be in Turkey at the time!! In order to look for Takashi, a mysterious man Sinclair came to Japan and brought Erina along with him. What is the "Black Trap" that awaits Erina in a foreign country...?! A shocking romantic suspense work filled with waves of love and hate!!