A story based off of the "Shuuen no Shiori Project", a song series by 150P and Suzumu. The stories are based off of Japanese children's games and urban legends such as one-man hide and seek, doppelgangers, mearry's phone and monkey paw.

On the normal, unchanging campus, it suddenly occurred; A murder case where a body was cut open, right into two.
On the other side of the unsolved case, the rumor-loving high school students became involved in a certain ritual.
From the extremely popular songs on Nico Nico Douga, begins the Project.

What is the “Bookmark of Demise”…?
Who is the traitor…?
What will the conclusion to this story be…?

So, can you solve this mystery?

At the risk of his own life, a young man sets foot in the ruins of a devastated old world. His name is Akira, and in order to claw his way out of the hellhole that is his birthplace of Slumtown, the boy became a hunter. In the wastelands he happens upon a strange woman, standing perfectly still, stark naked.
She is beautiful, but it seems that only he can see her. She exists incorporeal, tantalizingly beyond any touch, and she tells him her name is Alpha.
Alpha won’t show even a sliver of her real intentions, but with a wide smile, she brings Akira his first commission as a hunter. Akira takes the task, if only to become a stronger hunter, and having entered a contract, their dramatic lives in the hunting profession was set to begin.

From Stories of the Boy Hunter as recorded by the Eastern Hunters’ association.
Written post-collapse of scientific civilization.

I, an ordinary high school student, Kimizuka Kimihiko, who easily gets involved in things, was appointed to take care of mysterious attache cases by mysterious men in black suits. After meeting a beautiful angel-like detective girl, named Siesta in a hijacked plane, I became her assistant.

And from there–
[You deal with the beehive, and I’ll restrain the enemy.]
[Don’t make plans that make me the victim.]

We had those kinds of foolish conversations, all while being completely broke every day and fought against <The enemies of the world>. Even when there were hurricanes, the weather-beaten duo sleep past it. Sometimes when we saved money at a casino, we would jump around on the beds at a resort hotel, only to be broke again the next day. We would walk through deserts, traverse through jungles, conquer mountains, cross oceans– The great detective and her assistant would go through these dazzling adventures–

Until she died.

And this story starts from 1 year after that incident.
I’m the only one who’s left, but I carry on her remained wishes.
This story is far from over..

Kimihiko Kimizuka, a young man who four years ago became the assistant of a mysterious detective known as "Siesta" on a hijacked airplane. Together, Kimihiko and Siesta went on mind-boggling, globe-trotting adventures while combatting a secret organization, but all of that came to an end when they were separated by Siesta's death. In the present day, Kimihiko tries to return to an ordinary, boring life as a high school student, but things are never that simple, even though the detective is already dead.

From Kodansha:
When she was still just a girl, Kotoko was kidnapped by yokai. These spirits made her into a powerful intermediary between the spirit and human worlds, but this power came at a price: an eye and a leg. Now, years later, she watches out for dangerous yokai while developing feelings for a young man named Kuro, who is also special: an incident with a yokai has given him healing powers. He's surprised when Kotoko asks him to team up to handle renegade yokai, preserving the thin line between reality and the supernatural.

Shiragaki Seiya, a high school student and the daughter of a mangaka, is anxious to become financially independent so as to relieve the burden on her single mother. One day while on the way to school, she has an encounter with "The Spirit of the Chest, Aurelia de Medici," and thereafter finds herself thrown headfirst into a no-holds-barred otherworldly battle revolving around money.

In a deserted post-apocalyptic metropolis riddled with a mysterious material a young girl is searching for any signs of life and supplies.

Five years ago, my first love, Cha Mia, disappeared. Now, she has reappeared before me, completely changed.
An unexpected reunion at the police station… and she turns out to be a freshman at the same university?

The story of two people who thought it was over begins again on campus... or so I thought, but she still insists on letting the past go.

May I never be born again
Trying to throw yourself off the roof of the school
A boy, Ayumu, who lived an ordinary junior high school until half a year ago.
What pushed him to this point? And what is the true ending that awaits...?

On the way home, Jin and his friend Komachi are suddenly transported to another world full of strange creatures and Jin is killed by them, but somehow manages to come back to life, but as a tentacled creature !? This is the start of a dark tentacle fantasy!

From Nyan-Nyan Rampage:

"The final arc of the story begins...

When Takao Osugi receives the mysterious "Universe of the Four Gods" book from his mentor, Einosuke Okuda, he does everything to keep it away from his young daughter, Suzuno. But when disaster strikes Tokyo, can he still protect her from her fate?

Shortly after the tragic finale of Genbu Kaiden, young Suzuno Osugi's tale as the Priestess of Byakko beings to unfold!"

This is no different from ordinary villager life...
"There can be no one stronger than me in this world!"
To become the strongest, Yuria, the Sea Queen, went ashore in search of the Demon King. But when she looked at her reflection, she saw the face of a child. In exchange for her legs, she lost all her strength... Even so, still striving to become the strongest, Yuria begins a painful journey!

From Kirei Cake: Meet Sakai Hiroaki, a high school teenage mastermind with a genius-level intelligence and a lack of interest in anything that is easy to him. During one unlucky day, in an attempt to stop a student from committing suicide, he ends up committing suicide himself. After he awakens, he finds himself not in the real world, nor in heaven, but in purgatory, along with a group of others who did the same: commit suicide. Sakai discovers that he and his peers are subjected to never-ending intense death games in this world for reasons unknown to him, and he tries to find a way to escape. 

In a world driven by fictionalized friendship, courtesy of the program named "Real Account", the table suddenly turns, and the cybernetic world turns real! How will they survive?

This is part 2 of Real Account

I wasn’t reborn with talent or ability, but at least my knowledge from earth allowed me to stay one step ahead in this other world.

Magic exists here, and new progress was rapidly being made in science while magic stagnated in the name of tradition. Using my earthly knowledge and not bound by the traditional thinking, I was able to do things other wizards couldn’t even imagine.

Still, inadvertently becoming an undercover professor for a mysterious secret society at the renowned Sören academy was never in my to-do list!

If you think this has a happy ending, you read the title.

Sakuta is eager to finally have a chance to spend time with Mai again, but instead, he's greeted by a stranger who looks just like her. Apparently, Adolescence Syndrome is paying Mai another visit and has forced her to swap bodies with Nodoka Toyohama, a flashy up-and-coming idol... who also happens to be Mai's half sister! With no resolution in sight, each sister must pretend to be the other and go about their respective lives as best they can. Trouble is, it seems like Nodoka is preoccupied with something besides walking in Mai's shoes...

This manga shows you what you can accomplish if you eat the right food at the right place at the right time!

The Holmes Agency is a private detective agency nicknamed the Big-Eating Detective Office. Seiya Takano, who is known for have a huge appetite, becomes this office's new leader, after working on his own in the same field. Ryosuke Noda and Ryoko Izumi work under him, both also having a big appetite.

Murder, robbery, and kidnapping—the three solve each of many such cases in a most surprising way: their appetite results in marvelous speculations, deductions, and conclusions!

They eat at the murder scene. They eat on the track. They even eat dog food! They keep on eating and eating, focusing on the food to the exasperation of the police and witnesses. And every time after they finish all the food in sight, they finish off the criminal, too.

KUITAN is formed from the Japanese words for Big-Eating and Detective combined. Real gourmets solve real mysteries. The big-eating detectives are solving cases from their deep knowledge about food!

Rika is a new shy student at her new school. She’s always had troubles making friends because of her personality. Her past best-friend, Mirai, encourages her to change before she moves to the new school. Will Rika be able to gather some courage to change herself and make new friends?

In the imperial court, a young woman is put into servitude, Maomao. The tale is just beginning for the woman doctor/pharmacist from the red-light district, as rumors circulate about the emperor's children's lives being short-lived. Her curious nature and thirst for knowledge pushes her to action. To satisfy her curiosity, this young doctor/pharmacist will investigate the origin! What is shifting in the imperial court..!?

http://www.jp.square-enix.com/magazine/biggangan/introduction/kusuriya/