From MangaHelpers:
Yuto works for a magazine company known as "Kadokawa". His current project revolves around a mysterious phenomenon occurring inside the city. Someone or something has been placing stickers of a sumo wrestler's face all around the city in various places. No one knows who is placing the stickers or what their objective may be, but these stickers have been showing up in places for a while now.
Yuto now needs the help of an appraiser to solve this mystery. Searching through the web, he finds an appraiser known as the "Appraiser Q". Her name is Rinda Riko, and she has the ability to appraise anything (or anyone) and solve any mystery thrown her way.

Six years ago, Kasumi Shirou was the sole survivor of a plane crash. Though he lost normal vision in his right eye as a result, he gained the power to see into the past. Now a high school student, Shirou is bent on using his abilities to track down the man who murdered his mother.

From MangaHelpers: The Black Museum holds criminal memorabilia from the many cases that have been investigated by Scotland Yard. In this fictional re-imagining of the popular legend, a visitor comes to see a piece of particular interest, the leg of Spring-Heeled Jack. When the curator guides him to the piece, he begins to tell his story of the case of Spring-Heeled Jack, which began in the late 1830s. The earlier adventures of Spring-Heeled Jack involved an eccentric nobleman named Walter, who used his specially made suit to harass women. After an encounter with a very strong-willed woman named Margaret, Walter hung up his Spring-Heeled suit for good. Three years later, Spring-Heeled Jack returns, this time with a penchant for murder. Detective James Rockenfield first suspects Walter, but soon it begins to seem that someone else has taken up the mantle... [tethysdust]

From Dark Horse:

In a strange future where gifted, "hybrid" humans police the planet, Mina is a likeable tomboy with growing psychic powers. When a young boy falls into a coma after gazing into her eyes, it's clear that there's more to Mina than her pretty looks. This young boy, Inchang, grows up to be quite a daredevil, and his awkward, secret love for Mina fuels his protective fire when mysterious men arrive, bringing the violence of the "hybrid" world with them!

From Aerandria Scans:

Suzuhara Mugi is a fifteen-year-old on a mission. She is determined to somehow get onto the campus of Shoukei High School, one of those super super elite high schools. This school is huge and private and has tight security. Mugi is searching for her missing sister--her only remaining family--and she has been led to believe that someone or something on the campus of that school will help her in her search.

Unfortunately, that strict school security is preventing her from getting onto the school grounds. However, her luck changes when she literally runs into Midou-kun, the son of an insanely rich mega-corporation president, and elite person at the school.

Midou is not impressed with Mugi’s sob story about needing to get into the school. He is a very smug and arrogant rich guy. But he can be reasonable, and he eventually strikes up a deal with Mugi--he will get her onto the school grounds in exchange for some labor on her part. She must come to his house and work as a maid! Yeah, this is one of those servant girl stories, but there are a few interesting twists, namely the unexpected way Midou gets Mugi into the school.

Includes oneshot Baby Love in volume 1
Includes oneshot My Fiendly Robot in volume 5

In 19th Century England, during the Victorian Era, there is the Kingdom of Tarnina Ulaniborg. The Kingdom has a Royal Academy where Royalty and Commoners can study Astronomical Research in hopes of becoming a Royal Astronomer. Astel Paschalis attends the Royal Academy as a scholarship student with a certain hidden motive.

From Aerandria Scans:

Who am I? I'm Gi-ryum, a tall, handsome bachelor, and the coolest guy in the country who even makes O△ sama (Reference to "Yon-sama": Bae, Yon-Jun from Winter Sonata) cry at my beauty. One day, I received classified info of the princess enrolling in a regular high school. Huhuhu. Can I snag the princess with my irresistible beauty?! I will be the king's new son-in-law!

"What is the boundary between game and reality?"

The world is in danger. Strange juggernauts called "Angels" have started to appear all around the planet, presenting riddles called "Paradoxes" to whoever happens to be in the near vicinity. Answer right and your land will receive God's blessing. However, if you fail to solve the paradox be prepared to receive divine punishment...

Once again, the police are baffled by the serial killings of several young women. Kudou, a detective, is referred to a young girl by a friend. But this girl isn't what she seems - Kudou saw her at the crime scene. Apparently she's a vampire!!

The short stories of Tomoko Yamashita.
First girl: There was a girl in the middle of the gruesome incidents. ‘I thought that I was invincible.’
Second girl: A recollection of ‘a girl’ who didn’t love an excellent boy, ‘me’.
Third girl: The future where you are cursed when you are born. The only girl who wasn’t cursed is nervous about her undecided future. ‘She is pitiful for not being cursed!’.

Hiro's brother Atsuya is dating Hiro's childhood friend and secret crush Hikari. Hiro's affection for Hikari will lead him to commit an un-punishable crime against his older brother. At least, he thinks it is un-punishable, until he is kidnapped and imprisoned by a group of people wearing animal masks. The judging is about to start! Basicly same principles of "gore Game of concealed murderer" as in Doubt.

With the genius-level reasoning ability he inherited from his grandfather Kousuke Kindaichi, Hajime Kindaichi has solved a great number of very difficult cases. But he is just a regular high-school student. Though he wants to get closer to his childhood friend Miyuki, he can't manage to make a move on her because no matter where they go, a terrible crime always occurs! Kindaichi hardens his resolve and invites her on a one-night mini-vacation! "This time it'll work for sure!" he says to himself. As goes without saying, this manga is a comedy spin-off of the popular work Kindaichi Case Files!

The young Erwin Smith is a rising star in the Survey Corps, humanity's only hope of defeating the man-eating monsters known as Titans. Ruthless and dispassionate, Erwin’s mind is devoted to strategies and intrigue. But beneath Erwin’s feet is another world, the Underground, where humans are born and die surrounded by the garbage the Capital throws away. Here, the criminal Levi survives on his wits and agility. But when these two ambitious men cross paths, who will prove himself stronger?
The origin story of Levi and Erwin.

The protagonist, an author, tells the story of his encounter with a certain young girl ten years ago. During his college days, he once bore witness to a traffic accident wherein an elementary school student was hit by a truck. Strangely, the girl's friend, who was nearby, only went over to check on her after carefully saving the game she'd been playing just before. Soon afterwards, the protagonist found himself captured and confined by this girl.

Xolia applies for the title of "assistant to the Devil." In exchange for signing her life away, all she asks for is information. Now she's wondering if this was a good idea in the first place?

From Storm in Heaven:

Kyu's greatest desire is to become a detective. To fulfill his wish, he goes to take the entrance exam to get into the detective school run by Dan Morihiko, one of the most famous detectives ever! At the exam he meets Megu, Kinta, Kazuma, and Ryu as they all try to pass the grueling three-part exam. Kyu wants to solve mysteries, and he gets his wish: his first real case appears in the midst of the exam!

The setting of Devil Survivor 2 spans the whole country of Japan. It tells the story of Japanese high-school students who receive emails from a website foretelling their friend's deaths. Mysterious creatures invade the country, and the students enter a pact, enabling them to summon demons from their cell phones with a special Devil Summoning App.

This manga is based on the horror-style exploration/ero-game of the same name. Reiichi heads off for a part-time job interview, hoping to get money for a new bike, and his self-styled servant Kuro-senpai tags along. The "interview" is in a western-style mansion, but no one seems to be around. The two of them end up locked in the mansion and must find their way out.