What lies below Tokyo's subway system is more frightening than you could have ever imagined...in its subways there exists a boundary between this world and the next--the land of the dead, and the mysterious young man Seiya is its guide. In this collection of bone-chilling shorts, follow the twisted tales of death and hauntings that inhabit this horrifying underworld, where innocent youth fall victim to the ghosts who inhabit Tokyo's underground.

Note - this was originally a GlobalManga, and not of Japanese origin. However, all 3 volumes have since been issued in Japan.

From Easy Going Scans:

Once... Humans and Orcs peacefully co-existed, but at some point humans got greedy and started a war claiming the Orcs' territory. The diety-Lord who created all, got angry with the humans' greed and decided to punish them with 3 catastrophes. One of them was the "Dragons", divine creatures blessed with magic capable of doing almost anything. Now the Orcs, with a "Dragon" by their side, seem to have the upper hand. Will humans just sit back and see their land get destroyed? They are too devious for that... Their only good plan at that point is to abduct a "Dragon" to even things up. But how are they going to manage the capture of a being with so much power?

Note:Manhwa adaption roughly covers 2 volumes of the original novel Dark Mage (Novel).

December 20th, 198X. Mysteriously, people across the globe witness the same dark dream. Soon after, the number of humans unable to wake from their sleep begins to increase steadily. There are reports of life-like "R-dreams" that are experienced collectively and haunted with "Zel" - nightmare creatures. Hokuto, a struggling art student, is doubtful of R-dreams until he falls into one. There, he meets new friends, battles with the Zel, and tries to understand the nature of this dangerous phenomenon.

While taking a shortcut across campus to get to work, Shirahama Miharu interrupts a rendezvous between playboy Sumikawa Kaichi and his girlfriend and accidentally witnesses their breakup. Kaichi is not only unconcerned but actually helps Miharu jump the locked gate so he can make it to work on time?! As Miharu thanks Kaichi, offering to repay him with lunch, he blurts out that Kaichi is always with different girls because he's too fickle. No one's ever been so candid to Kaichi before and the novelty and Miharu are fascinating. Is this the beginning of friendship or...?

Akane has a crush on the princely Yuu, but when she finds out he's living with super attractive Kei, she makes a deal with the other girl to move out of Yuu's house. But Kei insists on moving in with Akane, and is now running her ragged with demands! Will Akane get any chance with Yuu or will all her time be spent with Kei?

A series of disparate but interwoven stories.

I Can't Tell Anyone
Haunted by the games they used to play as children, Hasegawa Midori struggles with her attraction to her now adult male cousin, Seiji.

I Won't Tell Anyone
Midori's sister, Minae, learns about her sister's marriage plans.

Everything Is Under One Sky
How Minae's relationship with her boyfriend began. When Minae finds love where she least expects it, she learns to see her surroundings through different eyes.

I Still Can't Tell
Minae asks her sister about the reasons for her breakup.

I Wan't to Tell Someone
A story on how Minae works up the courage to congratulate her sister.

Suprise Call
The office lady Mei gets an unexpected phone call.

Ending
Two working women, Tsugumi and Mei try to keep their lesbian relationship a secret, only to find it threatened by the world around them.

Collection of short stories:

1) Did I ever tell you that I Love you?
Soujirou was only in junior school when he confessed to the high-schooler, Masayuki. Masayuki didn't take him seriously. Now, more than ten years later, their relationship remains the same. Soujirou became an elite and Masayuki, a scriptwriter. Soujirou told Masayuki that he would wait for him. However, Masayuki saw Soujirou going to the omiai with his boss’s daughter…?

2) My family is interesting
During a 20 years middle school reunion Naito and Madoka meet again. Naito has financial problems thus he accepts Madoka’s invitation to move into his house, add a 15 years son and humor and hotness ensures.

3) Sunny day. Rainy day
New manager Tachibana visits former manager Koiso. At the entrance he sees a man leaving the apartment and he also finds the manager lying on the floor. Tachibana needs his help, but also does Koiso…

4) The other side of the tunnel
Continuation of Sunny day. Rainy day
After three months Tachibana and Koiso develop an on and off relationship.

5) The hole in the sock
A sweet story about friendship and maybe more between Ishikawa who is always late for work and chief Shimada who picks him up every morning.

6) Strawberrie's fragrance
Continuation of The hole in the sock.
Will this time Shimada finally admit his feelings?

7) Please be quiet for a while
Two lovers meet secretly, but one has a wife. Can such a relationship last?

8) Special Extra

Manga adaptation of Dante Alighieri's classic work "The Divine Comedy".

[Paradise Love Scanlations]
The mistake of that day caused two people’s parallel fates to intersect...

A small five-year-old girl named Subaru no longer has time for friends and play. Why is this? Her twin brother Kazuma is dying and gradually forgetting everything. Even Subaru. And so the girl visits him every day, talking with him and dancing for him, trying to make him remember her. And he always does by the end of the day. Encouraged by a friend to join ballet classes, the girl does so and falls in love with the dance.

Golf.. A sport where the prizes are really large. Meet Tadamichi Aoba also called Dandoh. A normal kid who's still in elementary school, he also really likes baseball. But because of a clash with his principal over golf, Dandoh switches to golf when he hears that he can earn about 30 million yen if he can win a tournament. When he was young, Dandoh lost his mother due to money problems. This is why Dandoh really wants to play golf, so he can bring his mother back. Under the guidance of a famous ex golfer, Dandoh aims for one thing !! To master golf and win a championship so that he can bring his mother back !!

From Illuminati-Manga:

At the turn of the previous century, the earth quaked. The earth's crust began to shift for the fourth time, centering around the coast of the Atlantic Ocean. The entire world's land mass was reduced to 3/5 of the planet, and the human population was reduced by a third. Put simply...the earth had gotten old. In 2039, there was only one country that continued to prosper, glaring around at the rest of the dying planet: Japan.

Todoroki Jin returns to Tokyo, the city where he was born, in hopes of finding his friend Ryoma. Little does Jin know about how Tokyo's changed since his last visit...

The oneshot at the end of volume 3 is called Warrior of the Holy Flame, Abi.

Recommended for fans of Riki-Oh

*Contains a oneshot called Kanegura: A young man takes a job as "house boy" for the "young master" of a rich family. The duties he's expected to perform are not what he expected however.

From Midnight Scans:

• Dakishimete Ii desu ka (Is It All Right to Hug You?)

“I can't bear to be separated from you, because you’re so cute.”
Because of Ushio’s excellent grades, he is forced to leave his beloved girlfriend, Ruka, and go to Tokyo University. Ruka is very beautiful, but also a little stupid, and other men frequently mess around with her, so he is worried that someone might take her from him, but if their relationship turns into a long-distance one…

• Hitorijime Shitai (I Want to Monopolize You)
Kaname has a crush on the top student Takashi, but being an idiot she thinks that she's never going to be good enough for him...

• Suki to Ienakute (I Can't Say I Like You)
Jun (?) is in love with his younger step sister Tsubomi, but he had already promised his dead step mother to always take care of her until she is an adult. As he takes care of her, he only grows more pain for this unrequited love, especially when she is soon to be moving with her boyfriend?

• Majo Sweets (Witch Sweets)
Chise has the coolest, manliest boyfriend Toranosuke who dreams to be a patisserie. Everyday, Chise hangs out with him to only eat his delicious cakes, but is that the only reason she dates him?

1-2) One side + The Long Kiss
Super-star soccer player, Gai, has a nightly duty to “service” his new boss, Yuito, the new owner of his soccer team and his old high school classmate. Is their physical-only relationship doom to eclipse their hearts…!? Or would the constant battle with Yuito’s formidable pride makes a frustrated Gai force to take drastic measures?

3) My First Man
Since he was a child Kazushi has admired young master Munakata Soma, so when his family's company needed help he asked to work for Soma in exchange for the support. Too bad he didn't specify how he was going to "work"...

4) Heavenly Hell
Gang leader Inatsuma Ginji is utterly fearless, except when it comes to loan shark Kanemaru Aran. His face hides a devious mind that has no trouble blackmailing Ginji into bed over a debt! But while Ginji's mind tries to resist Aran, his body is more than willing.

[Taken from FictionDB:]

It was simply blackmail.

Logan Miller was so determined that Talia Roberts come work for him that he was quite prepared to tell lies and blacken her name with her boss, John Diamond.

And John might well have believed Logan because he knew how ambitious Talia was. With little choice, she agreed to set up a catering service in Logan's new Brazilian office.

She was shocked when she discovered she'd also be sharing Logan's apartment. Worse still, she could really see no way out....

From NagareBoshi: Hina has just moved back to her old hometown, and transfers to the local school, North High. Little does she know about the rivalry between the gangs of North High and its opponent South High (the high school which her childhood friend, Kanata, attends). During her first week there, she is captured by gang leader Shuugo (enemy of Kanata).

New cop Asuku finds himself assigned to a special unit of inhuman police agents, tracking down similarly inhuman targets. Only time will tell which will kill Asuku first, a rogue criminal... or his partner.

From the Animeraider:

Daisy Luck follows the lives of four long-time girl friends, one who is now a housewife, one who is a baker, one who is an executive, and one who is not working. They're all about to turn 30.

At a judo tournament, Akutsu falls in love with Murakami. While jogging, they crashed into each other and Akutsu got hurt (not really, he had a nosebleed due to dirty thoughts). In order to tend to his "wounds" Murakami took him home...

Features Akutsu from Seito Kaichou ni Chuukoku