Nemuri Netaro will solve your sleeping problems, whatever it may be. Whether you can't sleep, have constant nightmares, or simply want to see better dreams, he's there to help. His latest customer, Tonko, has always been haunted by the same nightmare every night before she transfers to a new school. Tonko will now have to face the astonishing facts of the dream world with the help of Netaro!

Sorata is an everyday boy, who loves a girl called Futatsugi. When he was in elementary school he saw a girl in his dream, and on the very next day Futatsugi, who looked just like that girl, transfered to his school. Sorata holds on to that memory, but after he finds out about Futatsugi and what power she holds, can he still say that he's in love!? [From Owls Scans]

The witch, Marika, was exiled from the spirit world for committing a taboo in order to save the human child, Ryou. She mustn't get involved with human beings so that she can return to her world. However, Marika falls in love with Ryou and she plays "make-believe" with him when night falls. And due to the witch law, they are only able to go as far as touching each other's bodies?! Which direction will this unforgivable and forbidden love take?!

From Aurora Publishing:

Male by day & female by night...whoever looks upon her true form will meet with certain death. Abel is a member of the Nephilim – a unique race of people whose gender changes from day to night. Known as “Deathbringers,” it is said that whoever glances upon their bewitching nocturnal beauty will inevitably die soon after. Unfortunately for the playboy/Imperial soldier Guy, such an occurrence earns him this beautiful angel of death, hellbent on taking his life. Will Guy’s expert playboy skills be enough to conquer the beautiful Nephilim? Or will Abel succeed in killing the man who saw her true form?

N/A

A young boy, named Tien, hires a female hunter clad in red by the name of "Amu" to assist him in solving a series of murders & finding his beloved big brother.
SoltyRei -Aka no Shukujo- is a unique volume oneshot set in the world of the anime series, SoltyRei.

Jim is a young boy bound by a curse which seals him in the darkness of purgatory for 100 years. Bound by a curse, half of his heart is held by his best friend Luca. Due to Luca’s betrayal, Jim lost both his “best friend” and his “heart”. Once every 100 years, Jim is allowed to roam free for only 10 days and search for Luca whom he must defeat! Hatred replaces friendship and friends become enemies, now, who will be the one left alive? (Source: Iskultrip Scans)

Legend has it that on the last day of every year, demons and evil creatures would create havoc. People named this as "Nian". On one snowing day of this day, a pretty young man with long silky hair picked up an abandoned baby and named her as "Xue".

15 years later, Xue has grown up to be a young lady. One day, a young man appeared and told Xue with a gentle voice that could melt the coldest ice, "I've been searching for you.. for so long.."

Nakanishi searches for the truth about a classmate's murder so he can settle a grudge for her.

Every person in this world changes, it could be anything like their desires or personalities. What if behind a person smiles hides a dark malice or depression? How will someone react to it if that person have the ability to see their hidden facade? This is the story of a girl who can see the ever changing form of humanity as she dives into the mysterious realms of the unknown and real life.

My boyfriend transformed into me…

Shinba, who's always isolated himself and never made friends, finds stones that contain the souls of dead famous people. With his special power, he uses the stones to be people he thinks he could never be like.

From Storm in Heaven:

Supika studies at a school that teaches the magics of astrology and astronomy. Astrologers like Supika can use three magic items, a sun, moon, or star. Supika uses the star Spica (Virgo's brightest star), which is the most powerful item she can use at her level. In the school, however, women are stuck as third class students--they aren't allowed to reach the higher levels boys can. Of course, Supika doesn?t really agree with the obsolete rule and tries to get more powerful in order to become first class. Amano, the son of the principal, doesn?t agree with Supika?s free spirit and tries to stop her from becoming a first class astrologer...

Also inclued a story called Kaede.

Yi Sol is a boy born from a strange experiment conducted by a hospital... In his high school days sixteen years later, he is hunted by a mysterious organization. And as the days pass, Sol discovers that he has a strange power related to the mark on his forehead.

From kodanclub.com:
Soon after entering junior high school, Hinata Abe is hit by a truck, but survives with only minor scratches. This earns her the nickname of "the Miracle Girl" at school.

Hinata has a creepy dream the night after she leaves the hospital. She awakes to find her room filled with flames and smoke. When she cries for help, the Virgin Mary appears before her! Mary explains to Hinata what really happened to her: Hinata actually died in the accident 3 weeks ago!

A series of mistakes stopped her soul from going to heaven. Mary tells Hinata that she is dead and it cannot be changed. But Hinata pleads for her life back. Mary agrees to offer her a chance on one condition: Hinata must save 12 lost sheep within 100 days. She starts her mission to regain her life, wearing a pendant given to her by Mary.

A miraculous fantasy love story begins.

From DoujinToshokan:
Mare is a mysterious girl who has the power to summon monsters. Mare comes to a high school looking for individuals with relationships full of envy, hate, anger, and desire, searching for unjust acts and dishing out her own brand of justice. What is her purpose, and what challenges await her? And what awaits the students here with her arrival?

Alma is born a witch after her father makes a deal with the demon Mephisto. She seems to be able to travel through time and goes back to the middle ages in Europe, the Mayan / Aztecian time as well as the Roman ancient time and Nazi Germany.

From NOIR:
Memory eaters live on people's memories. They are originally death messengers who remove a human's memories when they carry souls. But some of them are charmed by the beauty of the memories and become Exiles: Memory Eaters. Dio is one of them, but instead of stealing human memories like other Exiles, he earns them by helping people. One day, Dio finds a girl who is losing too many memories from Exiles. He tries to help her, but Ces, who was a model death messenger, is around her. What is he doing here?

This award-winning classic story focuses on Marlee, an agent of the space empire sent on a mission to track down the opera singer Eroccus. There are three intertwining narratives which span planets and hurl the readers back 30,000 years in time. The narrative takes place in a non-linear fashion, unfolding across space and time, before folding back upon itself at its culmination.

Note: Winner of the Seiun Award in 1983.

Note 2: Gin no Sankaku was not serialized in a manga magazine. Based on content, it could be considered either seinen or josei.

Niu Qingqing is a regular 14-year old girl with a close cousin who is obsessed over Hanfu, or Han Chinese traditional clothing. Qingqing encounters a 'cute' mysterious young boy in early 17th century garb in her cousin's university campus one day, and decides to join the Hanfu club to find him...