In the Eniro Cinderella series:

Be my woman and I'll let you become a top singer! This is the speech made by famous music producer Yukihito Yoshizawa .Coincidentally, a female high-school student who wants to save her weak and sickly brother accept his terms by offering her voice and body. A passionate yet twisted entertainment love story thus begins!

From asdf scans:
In near future, mankind has been defeated by the viral parasites named "Gastrea." They have been exiled into a small territory and live in despair, side by side with terror. In this world trapped in darkness Rentaro, a boy living near Tokyo and a member of the "Civil Security"—an organization specializing in fighting against the Gastrea—is used to accomplishing dangerous tasks. His partner is Enju, a precocious young girl. They fight using their peculiar powers until one day, they receive a special assignment from the government. This top secret mission is to prevent the destruction of Tokyo. Set in a near future, this thrilling heroic-action story starts now.

From Dazzling Scans:

Matsuri had always been victimized and bullied because of her bright red hair. One day, two brothers, Natsume Fuuzou and Tsukuya, are hired to work at her family's bed and breakfast. It seems they have run away from home and are trying to earn their way in the world. However, there might be more to them that meets the eye... especially the strong, silent Tsukuya who manages to look past Matsuri's red hair and see her for who she really is.

A Genius who Fell into darkness. The God of the Underworld.
Akagi runs from a game of chicken where he almost died, to a Mahjong parlour where a man loses all his money to the yakuza. Akagi, who is only thirteen, tells the loser that his game needs improvement (although Akagi himself has never played before). Akagi replaces him in the game, and so a legend is born.
When the police come to check on the place to see if the kid that ran from the game of chicken is there the yakuza deny that Akagi was involved. In the end the policeman invites Akagi to a much more organized Mahjong game and from there, the legend of the Genius who Fell into Darkness continues to grow.

Inugami Tsubaki is the perfect girl and has her future perfectly planned: she's beautiful, smart, skilled in sports and loved by everyone. As the future head of the most powerful financial clan of Japan, it seems nothing can stop her. However, in her first day of high school, she meets Sarutobi Sanosuke, a wicked guy who outsmarts her and quickly becomes her enemy - what's going to happen between them?

This manga is about the black cat "Kuro" and the lone girl "Coco" living together in a large mansion. Cute, fun and somehow eerie... Check out this full-color manga full of mysteries!

From etc:
Ran's dream is to meet a prince, one of those you see in fairy tales. After several years Ukyo is back... to become her prince? With Ran living in her own fairy tale world and Ukyo not able to express his feelings and thus bullying her, how will this couple work?

This is a spin off story that occurs about three years before Spiral. One of the main characters is Imari, who is in love with the kid who wants to be a detective, and which also quit school running after Kiyotaka, and it seems he's dating a murderer without knowing it...? But how is it all connected to the blade children? Not long after, our favorite blade children from Spiral appear for the rescue, all manipulated by Kiyotaka.

Nanami Rei has always lived his life in his brother's shadow. He can't talk to girls, he's not athletic, and his grades aren't good. On the contrary, his brother Ren is smart and popular, but he has never judged Rei for his faults or lifestyle. One day, Ren goes into shock and mentions to Rei the name, "Wonder Rabbit Girl". Rei, seeking to find this mysterious figure, attends Ren's school, disguised as Ren himself.
Rei comes into possession of his brother's USB drive, which contains a list of the school's girls and their fetishes. Rei believes that one of these girls must be the Wonder Rabbit Girl.

The resonating Echo of the sword changes the boy's fear into rage.

From Jcafe24: Corpse Party: Blood Covered is about a group of high school friends in Kisaragi Academy. Kisaragi Academy was built on the grounds of Tenjin Elementary School, which was demolished after a string of disappearances and gruesome murders. After a mysterious earthquake, the students find themselves trapped in an alternate reality Tenjin Elementary School, where the murders of others trapped before them have continued unabated...

After years in an abusive household, Bell fled from her hopeless situation.

After being left bloody and beaten on the side of the road, she experienced a Christmas miracle.

From MangaHelpers:
This is a story of a group of college-age people who struggle with gender and sexual identity.
Yuki (nicknamed Yoshiki) is a girl, but she is terrible at 'being feminine.' She mostly dresses like a boy and is often mistaken as one. However, she has to wear a skirt and imagine being dominated by a guy in order to masturbate. Nagao Mikako seems young and innocent, and she uses that apparent innocence to sell her body as a fake 15-year-old. She knows her youthfulness can't last forever, but she enjoys tricking the men. Her friends have no idea of her sexual habits and believe her to be sweet and sheltered. Aiba Kaito is a pretty good-looking guy, but he wants to be Nagao Mikako. He often dresses as a girl, picking out clothes that mimic Mikako's style. Though he's into cross-dressing, he is still attracted to women. Will these young adults and their friends be able to handle their 'guilty secrets' and muddle their way through this confusing period of their lives?

When humanity was threatened 5 years ago, the boy who saved the world was driven to despair and became regarded as the enemy of all of mankind. And now a new crisis approaches humanity. The curtain rises on a gallant drama about a hero falsely charged.

A reclusive, disfigured man stalks a pretty, good-natured housewife. One day, he witnesses this woman's daughter being kidnapped.

From Asclepias Scans:

Park Min Gyeom is a human with a disease that makes him produce excess blood. Kim Chun Sam is a half-vampire who needs blood to live. So begins an unusual symbiotic relationship between "predator" and "prey."

Note: This series contains additional (optional) 18+ scenes.

This is a 5-volume manga series comprised of individual short stories that all have to do with coffee one way or other. Each of them is bittersweet with a philosophical bent.

After jumping into the sea during a cruise, Fukamachi Wataru, the famous musician, lands on an Hoshi Island, a place inhabited by folklore people. There he meets Himukai Antsu, a girl gifted in the arts of singing and dancing. With her, he is able to find his calling again, and once more create music. What he wants is to take her to Tokyo so that she can share her gift with the world.

The series is composed of four protagonists.

Nori: An energetic, upbeat girl who was heartbroken sometime ago due to her childhood friend. Now she is headed to meet Haruna, the lonely kid she always played with back then, but to her big surprised grew up into a hunk.

Kyou: The school's prince. From a distinguished family: he is handsome, smart, athletic and rich. He has never struggled for anything in his life, be it money or women. Haruna's sudden return throws him off momentum.

Saeka: She, Nori and Kyou are childhood friends. She is mature, composed and understands the two quite well. Although beautiful, she has been in love with her teacher since middle school and therefore never gone out with anyone. Will her feelings be answered or will she find an unexpected love around the corner!?

Haruna: The boy who comes back after having been away for many years. His reason for returning is unknown. The guy who’s clouded with mystery shows interest in Nori. Does he really like her or is there something else behind it...

Summary: Nori Sakurada is riding her bike one day, when she meets up with a boy she used to know when she was little. He has grown, but doesn't look very happy...

Also contains a side story called Himitsu no
H-kun in vol.1:
The well-known and popular Hakozaki-kun is the dream of every girl in Miwako’s school. However, he's hiding a secret! One day while walking down the street, Miwako notices him secretly taking photos of elementary schoolers!! Could it be that the famous Hakozaki-kun is actually… a… a pervert?!

As working woman and plant fanatic Sayaka Kōno was heading home from a drinking party, she found a handsome man sitting in front of her apartment who says, "Please bring me home with you," like a dog. With no place for the unnamed man to go, the two begin living together, and their "delicious" love story begins.