Even though J no Subete is 3 volumes long, each volume is a dynamic story in itself covering a particular stage of J's life. His life is a dark story and it's a very psychological manga.
Book 1 is about all of J's trials and tribulations throughout childhood, during highschool as he tries to find his place in the world and when he meets the somber Honor student Paul...
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 ch04-07
04 J no Subete v02-03
05 Barairo no Hoo no Koro v01 Extra

A collection of discrete but interconnected love stories centering around trains and train stations.

? Overpass Junction
Two people's lives intersect at a train station.

Andou gets an envelope passed to him in class that contains an erotic picture belonging to Kagaya Jin, the mysterious half French transfer student. A short, bittersweet tale from the Meiji era.
(Source: MU)

Do you believe in mermaids?

A boy met a boy. They were in the flush of youth.
They were in love that felt like a dream,
like sparkling soda pop.

In the Anata no Tame nara doko Made mo series:

V.1 - Anata no Tame nara doko Made mo

? Anata no Tame nara doko Made mo
Detective Takachiho Takumi had finally caught the elusive criminal Nanami Youichi after chasing him all the way to a remote island. But what will happen to the pair of them when they accidentally miss the ferry home?

? Magical Butler

? Non-non
Ishimaru and Yamada have been friends since the beginning of high school. Yet the closer they get, the more... awkward their friendship becomes!

? Non-non no Nochi

? Non-non-non

? Extras

V.2 - Naraku Izuko Emaki (Picture Scroll of Somewhere in Hell)
From Yaoi Is Life:
Anata no Tame nara doko Made mo: Heian Style Special

The serious and straight-laced government official of the Capital and Officer in the Right Division of Inner Palace Guards, Takachiho no Takumi, just can't ignore the annoying fake onmyouji, Nanatsumi no Hirokazu, who keeps hitting on him. And now he's forced to work on an accident involving ayakashis! But for the pervert Nanatsumi, he uses every chance he has to turn the situation into a dirty one!

The secrets under the uniform, that none of the classmates knows.

A meeting between a caged bird and a murder.
A meeting that never can re-united.
A meeting that so short yet so sad...

A mysterious story about a poor young man who orders a kind of tea called Huan Ying – “The Illusion”. He asked for a small quantity - just to have a taste - and was granted one cupful...

Paul, a serious honor student, meets the violent and rebellious Andrew in their all-boys school. What follows is a story of the struggles of youth and painful but powerful self-discovery.

Daddy, Mommy and Mika make up the perfect modern family. Mika is Daddy's little princess, and he won't hand her over to any one. But when handsome Atsushi-sensei at the daycare center becomes Mika's perfect prince, sparks fly. What ever will Daddy do?

It's a very short but sweet oneshot about an artist and her portrait model.

1. Ano Hi, Seifuku de (That Day, in the Uniform)
2. A-senpai
3. Shishunki
4. Hadaka no Boku (Naked Me)
5. Tenkousei (Transfer Student)
6. Nikoichi

The Butler Tsuruhami tries to turn away a door-to-door salesman, but it won't happen that easily...

From pinklotus89:
A story about a girl in her death bed finding another chance in life in the body of a doll. But is the girl in the bedroom the same as the girl in the sculpture room? Can the doll master make her dreams come true?

Though Rihito’s always been a loner, lately he’s grown close to his classmate, Hikaru. The two of them have even fallen in love and tentatively started dating. But when Rihito’s mother ends up in the hospital, the stress of it all becomes too much for him. Hikaru wants to be there for Rihito, but can Rihito learn to open his heart and rely on another person? (Source: Seven Seas)

From Aestheticism:
The story happens in a circus in Paris in the 1970's. (...) Much is made of the romance of the circus atmosphere, of flying through the air on a trapeze, etc etc. Think cirque here, not circus. We're doing Old World riffs on the romance and tawdriness of the ring. There are no elephants in tutus walking on their hind legs; it's slit-eyed jugglers and daring death-loving trapeze artists and sad Pierrot clowns, even if the Pierrot clown - our hero, Torinosu, 'Bird's Nest' - has a false red nose. The tawdriness comes from the circus master pimping out his performers to anyone willing to pay. (...) And there's tanbi decadence - ghosts who wander into the action looking like teenaged girls even if they're the hero's brother, and abandoned neurotic women with a thing for inflicting pain, and buracon and possible murder and unspoken pining and a hero who looks about to perish at any moment from terminal angst.