From MangaHelpers:
17-year-old Awaya Mugi and Yasuraoka Hanabi appear to be the ideal couple. They are both pretty popular, and they seem to suit each other well. However, outsiders don't know of the secret they share. Both Mugi and Hanabi have hopeless crushes on someone else, and they are only dating each other to soothe their loneliness. Mugi is in love with Minagawa Akane, a young teacher who used to be his home tutor. Hanabi is also in love with a teacher, a young man who has been a family friend since she was little. In each other, they find a place where they can grieve for the ones they cannot have, and they share a loneliness-driven physical intimacy. Will things stay like this for them forever?

Volume 3 contains Nyan-Nyan Oratorio:
The lonesome struggles of the only living being on Earth.

From Senpai Scans:
Yori, a boy who is bad at expressing his feelings, Haru, a girl who's his childhood friend and Subaru, his best friend. When did the three's relationship change...?

Like the star's light, our feelings guide us...
A sensitive four-chapter story that encapsulates our story where we, though clumsily, lived with our might.

Includes oneshots:
1. Bambi N' Lion
2. Toi tonari yori
3. Kotoriasobu wa ine wa koi o shiranai
4. Sorekara 3-nen-go

Shinozaki Mikoto is a student whose life is really routine. Going to school, going home, going to school, going home... nothing changes... until the day the girl he likes talks to him and introduces him to cycling. His life now has a new meaning, and a bright path has shown itself to Shinozaki. Experiencing both failure and success throughout his training, he works hard to become the best cyclist in the world.

Kanako is a young woman who is running an old book store. One day, a customer comes in who shares her taste in books. He's a teenager named Akio, and he and Kanako quickly find that their taste in books is only the first of many ways that they fit together well. Kanako immediately realizes she wants him, and soon blurts out awkward things, like proposals of marriage and cohabitation. Despite their different ages and their awkwardness, it seems like their relationship has the potential to grow into something beautiful.

Summary From Batoto:

The 12 Deities are running rampant on earth!
And Sages who're above humans are planning to
take over the earth...

A collection of short stories:

• Boketsu

• Taikutsu na Tsuki

• Johnny kara no Dengon

• Round Girl

• Nade-shiko

• Chinpa

• Jinsei Kaya no Soto (Kari)

Kanade Ichinose is a violin major in his third year of college. When he first entered the university, everyone had high hopes for him, from his professors to fellow students. However, he distances himself from everyone and everything except music. He refuses to participate in competitions, as he see no point in it. When it comes time to think what he wants to do with his life, he just eases into his mother's music tutoring business.
He realizes that he is a boring and pessimistic guy but has no idea how to change... or what to change into.
Then, one day he sees a girl standing barefoot in the snow outside an apartment and thinks, "If it's for her, I can change." This is the story of Kanade's entry into the world of overclocking.

When the Majin awoke from the depths of darkness, the deity of fate chose six heroes and bequeathed them with the power to save the world. Adoretto, a boy who proclaims himself the strongest on Earth, was selected among the Rokka no Yūsha (Heroes of the Six Flowers), and he goes to the rendezvous point — but seven have gathered there. The heroes suspect that someone among the seven is the enemy, and the initial suspicion falls on Adoretto.

From September Scanlations;

Here starts the Konya spinoff series, focusing more on Gorou and Verde! There’s plenty of Endou and Rikiya as well, but this story will spend more time telling the story of these heretofore side characters. The story takes place immediately after the last Konya chapter, so you can think of this as Chapter 20, just less focus on Endo/Rikiya and more on Gorou/Verde.

Yamada Tarou is living a regular life, until the death of the father he never sees catapults him into the role of the 13th King of the holy Phantasma kingdom. Now that he's king, Tarou has become the target of assassins, and all he has on his side is a mistress, Princess Kaguya, whose goal is to make Tarou a worthy king.

From ShoujoMagic: Yumi is a college sophomore. She's going out with Kouta, who's in her same circle. Just when she's been taken in by Kouta's boyish manner... she gets pregnant. What will become of Yumi and Kouta, who worry that they can't have this child...?

So there's this guy, right? His name's, like, Masato or something. He's got bags the size of suitcases under his eyes. He wakes up one day to find that cloud/sheep things have gone and kidnapped everybody. He also meets this boy/girl/sheep named Dori that's all sunshine and rainbows and stuff. They go around looking for people that haven't been taken by the sheep, with Masato beating sheep along the way with the power of beauty-sleep or something because of a promise he made to his dying mother. How's that for weird?

The "after school love comedy" story follows Hana, a small, quiet girl who attends a discipline training all-girls school because she was attracted to the cute uniform. She secretly works at a fancy shop as a part-timer, and one day Hina, the school's super-slender beauty, joins as a new employee.

The Japanese government developed a military project where they created "Iron Princesses", schoolgirls who were altered to strengthen their body by replacing their bones with steel and artificial muscles. The Iron Princess are experts with the katana and are allowed to fight in the streets to determine the cream of the crop. Those who repair the Iron Princess are medical experts called Toui and they work to maintain and improve the girls. Sakuradamon is an academy built to train girls like Asami Honoka, an Iron Princess and Nagamitsu Yomogi, a Toui. Asami is a mysterious and powerful fighter while Yomogi is a medical child prodigy and they have to work together if they value their lives on campus.

From AQUA Scans: Japan, Year 2X65, Tokyo. As the population continues drop due to a mysterious disease, through a certain incident, the fates of two young men, the orphan Noel, and Rikka, the heir of a distinguished Mafia family, will cross... A thriller, depicting the tale of their Bond of Blood...

Nanase Haruka is a sixth-grade elementary school student who loves connecting with the water and feeling the water as he swims, and he attends a local swim club together with his childhood best friend Tachibana Makoto and Hazuki Nagisa, one year younger than the both of them. Then, one winter’s day as graduation draws near, Matsuoka Rin transfers into Haruka and the others’ school from another swim club. Through swimming, Haruka strengthens his bonds with Makoto and Nagisa, as well as with Rin–at which point Rin, with his passion for the medley relay, suggests they form a team together and enter a tournament.

This is the novel that the anime Free! is based on in manga form at last! (September Scans)

15-year-old country girl, Suzume Yosano, has to move to Tokyo to live with her uncle due to her father's transfer. She bumps into a mysterious man who ends up taking her to her uncle's place after she gets lost. Turns out, Suzume will be seeing him a lot more often once she starts school because... he's her homeroom teacher!?

Included in the manga is a oneshot story called Tsuyu Kaoru (A Love Story in Moist Rainy Days) in volume six:
A romantic and melancholic love story behind a red umbrella.

From Yaoi Is Life:

Kadokura is the student council president. His father, who is the coach of the track and field club, allows various members of the track club to board in his home, an event that causes alot of stress for his son. One main source of stress is the ace Kima, who has a huge ego and constantly bothers Kadokura. While Kadokura has to deal with this until he graduates and leaves the house, suddenly, one day, Kima kisses him. Consequently, Kima begins to kiss and touch Kadokura, but Kadokura has no idea why. It looks like if things keep up this way, Kadokura might start thinking that Kima likes him...

Kenji Sakuragi is a poor lawyer and ex-motorcycle gang member looking for an opportunity to boost his career. His chance finally comes with the nearly bankrupt and notorious Ryuuzan High School, referred to as "baka gakkou" (stupid school) by some. There, he sets up a special class that aims to prepare students to take and pass the entrance exam of Toudai.

Won the Kodansha Manga Award for General Manga in 2005.

Short story about the Udou brothers' very different love lives.