From Tokyopop:
In the year 2068, the Brain Computer, created by humans to be the core of a machine-driven Earth, itself creates Leave, an android that far surpasses the abilities of humans. With mankind now an unnecessary aspect of the Earth ecosystem, Leave, along with her 'father' Fenrir (the human scientist who raised her), destroys humanity and in its stead creates the four 'Mothers' who in turn create an android race modeled on Leave known as the Selenoid.
They divide the world into four parts, each ruled by a Mother, and then further sub-divide the android population into hierarchical levels with the strong at the top and the weak at the bottom. A virtually perfect society ...
And it would have remained perfect if some of the surviving humans hadn't formed a revolutionary group together with some of the lower caste Selenoid with the explicit purpose of overthrowing Leave and delivering the Earth back into the hands of the humans.

From ShoujoMagic:

When her mother decides to remarry, Honoka inadvertently becomes "family" with the rising star she's infatuated with, Masaki Izumi! Honoka can hardly wait to become like the families in Masaki's TV dramas... but the guy himself is a far cry from the roles he plays. In real life, Masaki is seductive, rash, and forceful, and he's decided Honoka will become his woman...!? *gasp* But that would be... SCANDALOUS!

Manga adaptation of BlazBlue game.

They arrive in silence and darkness. They descend from the skies. They have a hunger for human flesh. They are everywhere. They are parasites, alien creatures who must invade - and take control of - a human host to survive. And once they have infected their victims, they can assume any deadly form they choose: monsters with giant teeth, winged demons, creatures with blades for hands. But most have chosen to conceal their lethal purpose behind ordinary human faces. So no one knows their secret - except an ordinary high school student. Shinichi is battling for control of his own body against an alien parasite, but can he find a way to warn humanity of the horrors to come?

Won the 1993 Kodansha Manga Award for General Manga and the Seiun Award for Best Comic of the Year in 1996.

Romantic oneshot collection

1) Kimi no Himitsu (Your Secret)
2) King and Me
3) X-Mas for You
4) Under those Heavens

(Source: Simple Scans)

Escaflowne, the God Protector of Fanelia, has been stolen and the country is left in ruins. Desperate to find the key to Escaflowne's seal and recover the legendary guymelef, Van Fanel, Prince of Fanelia is sent to Earth, only to find it in the possession of a high school girl, Hitomi Hoshino. With enemies chasing them at every turn, can the two reclaim what was lost? Named Messiah Knight when serializing in Monthly Asuka Fantasy DX, but renamed to HITOMI when tankoubon were published.

Nemu is back home. What's gonna happen with Junichi's life after this reunion with his sister? "Da Capo" in Italian means "From the beginning"... then will we see the end to this romance?

A girl being anxious of her relationship with her boyfriend since there is still no progress.

Takatou Iori, a high school ninensei, while on his way to school to confess his love to classmate Kusanagi Mikuru by means of a love letter, gets ran over by a truck to save a cute elementary schoolgirl.

*manga is based on a true story and the true story was done in 2ch*

It's about an Otaku guy who fell in love with this beautiful lady and tries his best to get that girl with a lot of help from 2channelers (people who goes/posts on 2ch).

This story has become very famous in Japan and I believe they now have novels, several series of Manga (both Shoujo and Shounen), movie, drama, play, etc, etc.

From Dan of Population GO:

"Mutants have popped up in Tokyo. These mutants are the relatives of gods and upon consuming human blood they transform into their awakened state which resembles the god that they are related to. Hachi has a nose as good as any dog's. After his best friend is attacked by a mutant he drinks her blood in order to save her."

Takaomi Matsubue and Arika Togawa are second-year students at the same high school. By some strange quirk of fate, they started dating. Matsubue-kun is a really weird guy (in truth, other people just don't understand him), which causes Togawa-san to ponder: "Why do I like this guy anyway? Why do people fall in love?"

They encounter a baffling mystery: Tsugumi Yoshimoto, a girl who has been sleeping, sleep-eating, and sleep-walking for half a year. According to Touko and Rinko Mishima, sisters who are also well-acquainted with the structure and interpretation of dreams, this is a matter that concerns them all...

Kaname lost his older brother Souta in an accident, too young to die at seventeen. They are so different from each other that the only thing common between them is a book written by Tsujiura Ryousuke. What happens when Kaname meet Tsujiura-san, the author both brothers respect and admire, after Souta’s funeral?

From Kotonoha:
Based on the award-winning novel by Shinji Kajio, Memories of Emanon tells the story of a mysterious girl who holds a 3-billion-year old memory, dating back to the moment life first appeared on Earth.

Jewel and Canary are twin brother and sister. One day they had a fight. Will they be able to make up?

Naho is having trouble keeping her feelings in check when taking care of her sick friend Mana.

An unemployed bachelor meets an enigmatic vampire. What will happen? Find out in this hilarious webtoon. This webtoon is a Best Challenge on Naver.

The shinden (temple knights) are held responsible with the duty of fighting demons for the sake of the holy maiden, who's the symbol of the church. The holy maiden, unique to this country, exists to help save people from a mysterious illness that happens around the time of a new moon. Due to this, many people became followers [of the church]. Murray, a shinden, was brought up under the holy maiden's guidance, but, what kind of mysterious living is it if he supports the holy maiden, involuntarily? Even if he knew the church distorted its teachings.....?

Here, the curtain rises to Izayakaku's Sakamaki Yukisato as she gives us a twist to a fantasy world.

In the near future, Japanese government successfully developed a new energy "Ψ" called psi that have been laid under its land from ancient time. Sakuya, Goht and Leon who are special forces "Kerberos" who dedicate themselves to protect the secret of Ψ from various powers. The strongest solder is a beautiful girl, Sakuya. She has a trauma but stands with team members, Goht and Leon, who admit her strength and weakness.

Oneshot about pilots killing creatures from sea