From Tranquil Spring:

Short random school life chapters about a group of girls who attend Watermelon Junior High.

From StarryHeaven:
Ema is obsessed with ghosts, and is even part of her school’s occult club. She’ll do anything that has to do with some crazy superstition about ghosts or spirits, and make sure that she goes out of her way to do it. Ema is known for this at school, and the series follows her pursues to find ghosts. Ema, unfortunately, cannot see the things that she loves, unlike a few of her friends…

Included one-shots:
Volume 1: Shuugaku Ryoko no Susume
Volume 3: Time Capsule and Happy End no Tsukurikata

*Scanlators stopped because of lack of interest in chapters 2 and 3.

From MangaHelpers:

On his seventeenth birthday, Amamiya Kota was going to ask his classmate Misora Hiyori out. Tragically, he dies in a car accident but is given a second chance back in the living world on borrowed time. He gets entered into a competition called the 13 Game where other people like Kota who were supposed to die return back to the world and given an option: locate and kill 13 other players or suffer the fate of death. Each player is assigned to a handler, mysterious beings with special powers, who use them as if they were characters in a video game. Kota’s handler, Merume, explains that there are players like him all over the country, each with a unique ability that helps them kill, and Kota has to kill 13 players within 1 year. With his demon hands ability that was inspired from his hobby of magic tricks, Kota must unwillingly participate in this cruel game if he wants to live. [vyc]

From: Easy Going Scans

If you could find out a little something about the future, what would you do? Get rich off of the stock market? Use the media to become famous as a prophet? Or…

Seducing the guests to make them pay the most, that is the job of a host. Takashi, currently the No. 1 host, is an apparent professional when it comes to being a host. Being a host isn't Takashi's only job. The Persona XII, guided by the stars are to preserve the balance of fate. The eyes on an assassin serves the guidance of the stars.

Satsuki Kakeru lost his sister by suicide and has been living a dull life ever since then. One day, he is transported into a bizarre world "Red Night" along with his friend Minase Yuka and six other classmates. In order to survive and escape from Red Night, they must defeat six black knights in order to return home.

From Heroines of Fantasia:
16-year-old Tsukimi Hina decides to get a part time job as a maid, and successfully passes her interview. One thing though: she can't use modern technology inside the house whatsoever?! Which means no vacuums, no cellphones, no laptops, etc. What is up with her twisted, but handsome, employer Asakura Shiyuusei-san? And what exactly is he hiding in his storage room...?

From Intercross:
16-year-old Hina's first job is with a 19th-century British enthusiast, Shuusei-san, as his maid. Even the way of cleaning has to be from the 19th century! Even so, this sweet gentleman makes Hina's heart beat so fast! There is actually another person in this residence, Mary Lou. She's as cute as a doll, but... she's, she's... a ghost?!

In this small town, within the 49 days after a person dies, you can see the dead's spirit. She once admired this small town where you can still spent time with the ones precious to you within these 49 days, but...

Includes two oneshots (not yet scanlated):
Soko ni Koi Ari (そこに恋あり)
Kimi wa Nanimo Hoshigarazu (君は何もほしがらず)

3, Street of Mysteries explores the fantastical-poetic vein that has forged Mizuki's reputation in Japan. The stories contained in this series hold in common the obsessive ideas of immortality and of life after death. Skillfully blending a range of black humor, drama, and questions of morality, Mizuki shows once more his profound understanding of the human soul.

(paraphrased from Astiberri)

From Noctis Op.92:
What exactly is the difference between a robot and a human?

In a dystopian future in which robots are becoming increasingly commonplace, a young boy named Hogu lives in near poverty with his grandmother and sister. Though he innately possesses a kind soul, he is ostracized by his classmates and frequently bullied. At the beginning of the story, we find Hogu, friendless and alone - until he meets a robot girl...and our story begins.

Thief Gintonic seeks the mysterious treasures known as "The Three Hearts". One night a mysterious woman falls from the sky claiming to be an escaped Princess from a sacked castle. As fate would have it, she has one of The Hearts. But is she really who she says she is? And will Gintonic let her live to fulfill her mission?

From ShoujoMagic:
1. 38°C
Taiji's normal body temperature is 38 degrees Celsius, or so he says, but Shiina thinks he's full of it. Taiji is a friend with whom Shiina can always--and does always--fight... Until Taiji unexpectedly confesses his love! Shiina begins to run a fever, but is that the only reason she's getting so hot...?

2. Solution Maze

3. Heaven in Jail

4. Winter's Aquarius

Collection of short stories:

• 37℃ Kissu
Naoki was a very cool and good looking guy, but somehow after meeting Fumika-chan, he's not cool at all, but very cute?!

• Himitsu no Namida (Secret Tears)
He saved his second button for her, but on their last day, she handed him a love letter to give to his best friend. Instead of delivering that letter, he kept it himself, and asked her to go out with him instead...?

• Caramel Kiss
Atsushi-sensei is Kawahara's first love, will he be able to accept her affections?

• Shounen Knife
Until Riki moved in, the house next door to Mimi's was always vacant. Riki saved Mimi's cat, but it seems that he isn't as well mannered as she first thought?

• Extra from Kiss, Zekkou, Kiss Bokura no Baai.

1-3) 37°C no Boyfriend
Wakaba got locked up in an elevator with a completely strange guy. Moreover, they happened to share a kiss. He's someone she'd never meet again... or so Wakaba thought, but it turned out that that guy, Chitose, is the boyfriend of Nao, her friend!
Nao introduced a surprised Wakaba to her upperclassman in her club, Takaomi, but no matter what, Wakaba can't forget about Chitose...
- Awakened Memories

4) Tsukiakari no Himitsu

5) Haru ni Naru Made Matte
(Also included in Houkago, Kimi to Koi o Shite.)

About a play-girl goddess from heaven who is stripped of all her 'goddess' powers and reborn as a human. The story progresses as her incarnated character learns to live, love and find what true happiness is all about.

In this story, our heroine, Shinobu, is a female ninja in training. The only trouble is, she seems more interested in hanging out with her friend Kaede, and the fact that her ninja Master is a round yellow thing that pretends to be hawk isn’t helping.

From Boys On Boys Love:

1-2. 2-dome no Koi no Hajimari wa
After being harshly dumped by his lover, Kousaka Yuuki, a shop manager at a restaurant, swore that he would never love again. One day, he meets his ex again when he unexpectedly shows up at Kousaka's shop. It was then completely exposed to Matsuoka, a kouhai at work, that he dated a guy. Kousaka was shaken that his past was known to Matsuoka, and worried that he would look down upon him, but Matsuoka forcibly kisses him and says "I love you" to Kousaka...!?

3. Gekiai Honey
Sasaki Ryoutarou, a part-timer at a restaurant leading an ordinary life, suddenly met his old classmate, Mio. Mio was once a gloomy guy ignored by all, but is now a cheerful, completely changed guy. He claims to have been searching for Ryoutarou to be his lover because he couldn't forget about him, even after being rejected a long time ago. Mio changed his style because he had heard that Ryoutarou's type is a cheerful person. Ryoutarou refuses to go out with him, to which Mio responds: "go out with me for a month, if you don't fall in love with me then I'll go back"...

4-5. Honey Trap
You is in love with his best friend Shinji. Afraid of ruining his friendship with Shinji, he doesn't confess, and breaks off all contact with him. Three years later, running away from some stalker, he enters a building and asks for help. However, it turns out that the man living there is his ex-friend Shiniji, who is now a detective...

But what will happen when Shinji suddenly asks You to be his lover?

6. Bokura no Koi no Hajimari wa

- Extras
Is a small continuation about the first story.

N/A

A collection of stories:

1-3. 2 Shuukan no Adventure

4. Himeko-chan

5. His Left Eye
A story detailing an encounter between Gerry and Eugene from Barairo no Hoo no Koro, as adults.

6. Belgian Waffle
Andrew, from Barairo no Hoo no Koro, takes a stroll with his old father, bringing about some surprising discoveries, aside from the fact that Belgian Waffles can be sweet.

Timeline (from Oriolidae & Sparviero):

01 Barairo no Hoo no Koro v01 ch01-05
02 J no Subete v01 ch01-05
03 2 Shuukan no Adventure v01 ch05-06
04 J no Subete v02-03
05 Barairo no Hoo no Koro v01 Extra

From Chibi Manga:

5 years ago, Shin was Yumika's private tutor. Now this Shin-kun comes to Yumika's high school as a teacher trainee! But their love from 5 years ago will most probably start to bloom again?!

From Midnight Scans:

Yumika’s first love was her tutor Shin. As she hope to meet Shin once again, which really happens, how will Yumika proceed on to confess to Shin about her feelings…