Kiyomi wonders how best to give her Valentine's Day chocolate to her girlfriend Kaoruko

Roots of A is essentially a short manga featuring Akiyama during his senior year of college. In it, Akiyama and four of his classmates are taking a criminal psychology course and given an assignment where they must construct a profile of a person based on a letter they sent. This outcome of the assignment, plus what the professor says afterwards, is what prompts Akiyama to enter grad-school and continue to study psychology.

Includes other oneshots:
Nine Darts
Three Phase - The Forbidden Divination (1)
Three Phase - The Forbidden Divination (2)
The Tale of Shinobu Kaitani's Dog
@Lovers

Manga about this

http://en.wikipedia.org/wiki/Little_Fighter_Online

and this

http://www.littlefighteronline.com/

maybe....?

http://www.lf-empire.de/en/lfe-v90/lf-empire

From MangaHelpers:
Kousuke has a boring high-school life, but he sits next to his crush--the really popular, cute Tsukahara Meguru, who has a cool, stoic personality. One day, his parents announce that they're moving, but that he'll still be able to attend the same school. The new apartment building has a lovely river and friendly neighbors... and it is next door to where Tsukahara lives! Outside of school, she seems to have a completely different personality, friendly and a little quirky. She makes him promise not to tell the others at school how she acts at home, but why does she put on such an act for her classmates?

In the air above Okinawa, a strange figure is floating and disintegrating hellfire missiles from US helicopters. Experts from different disciplines and organizations have gathered to figure out what's going on.

A former mangaka falls into poverty after becoming disillusioned with life and abandoning his trade. He unsuccessfully attempts to start a business selling rocks by the riverside to feed his family.

A train is split into three sections: Morning for the lowest-class passengers, Afternoon for the middle-class, and Evening for the upper-class. It is running through a country only just starting to use electricity for power, rather than their source of Rainbow Stone. With the country in a era of change, will something begin to derail? Join Toky Towy as he works and learns life lessons aboard the transcontinental locomotive, the Rainbow Stone Train.

Hachi has perfected his poker face to hide his true feelings from his friend Rin, but maybe he didn't have to.

The locomotive called the Rainbow Stone Train runs, not on electricity, but on the energy source called, "Rainbow Stone." Inside, the train is split; from the extremely high class Evening carriage, to the average Afternoon carriage, and finally, to the cheap, but cramped and noisy, Morning carriage.
Employed as a crew member of Morning, Toky Towy struggles daily by the side of his strict superior. While going through various encounters and farewells again and again, he...

From Sentimiento Yaoi: Mimasaka-san is hiding a big secret that will lead to his perdition... when Kagaya finds out and makes use of it to catch him.

Yuuko wants her best friend to be happy, so she supports her friend with her crush, a senpai. Meanwhile, there is another energetic senpai who is aiming for Yuuko...

In a ruined city, Takeru comes across a suicidal young girl named Konoha. She's deathless, and she's being used as a guinea pig by a cruel organization. Seeing no meaning to her life, she fled her captors to seek a way to end it. Takeru has a lot in common with Konoha-- he's also deathless. He's made a life for himself, though, locating people by contract. After he rescues her from her pursuers, he convinces her to continue living. Maybe she'll be able to find a purpose, as she and Takeru face the future together.

A young coffee shop worker dreams of finding love.

Ibuki, returning to his childhood town for his grandmother's funeral, is not at all shocked to find that nothing in the little town has changed. Except that he finds out that his grandmother had remarried and that he is now succeeding her as the "Mononokemono."

N/A

Based on the popular noitaminA anime of the same name, Mononoke is the story of a mysterious medicine seller (Kusuriuri) who traverses cities, villages - and, seemingly, time - on a lone quest through ancient Japan in order to vanquish "mononoke," supernatural entities created when a strong human grudge or desire combines with a type of free-roaming spirit named ayakashi. But his quest is not so simple, as the darkness of humanity is endless and makes figuring out the Form, Truth and Regret of the mononoke - which are prerequisites if he is to be able exorcise them - an incredibly dangerous task which rarely fails to turn up casualties.

Each volume or pair of volumes follows the eponymous arc from the anime:

V.1-2 - Mononoke (Note: this is the adaptation of episodes 9-11 of Ayakashi - Japanese Classic Horror, a supernatural anime in which the medicine seller was first introduced before the arc's success prompted him to receive his own series)
V.3-4 - Mononoke - Umibouzu
V.5 - Mononoke - Zashiki-Warashi
V.6 - Mononoke - Nue
V.7 - Mononoke - Noppera-bou

The story of a boy and a girl who met in an era of witch hunts.

A coming-of-age manga about two kids who are curious about sex.

From ShoujoHearts:

Kotone, who thinks of herself as an average office worker, is fascinated by dazzling and mysterious things. Meanwhile, it's revealed that Shishidou, a good-looking superior in the company, is the enigmatic "Love Deity"! Hearing the rumor that a person's wish for love instantly comes true if they pray to him, Kotone seeks out Shishidou.

Honami Mikazuki is in love with her teacher Miss Kanno. When Honami witnesses Kanno kissing another woman she uses the information to get closer to her.