From Sync Scans:

If you know the one you loved was known as the “Murder Devil”, would you kill your lover? Or, would you wait to be killed?

Includes:
Toshi Denestsu Yomigaeru Sattujin Oni
From a psychological test, he is diagnosed as having a trait of a murderer, and because of that, she is attacked with a lot of unsolved incidents?!

Migigawa no Akai Yami
Is this a curse from the girl, who was bullied and committed suicide, which causes her right eye to see only the color red?

Michela is a 13-year-old student at the Clausura Academy of Magic and Sorcery, a school for magic-holders aspiring to become “Wizards”. Unfortunately, she lacks even the most basic control over her powers, with all her attempts at spell-casting inadvertently ending up in explosions.

One day, Michela sets off a particularly nasty explosion that stood to consume anything and everything around her.

Just when death seemed imminent—

A young man appears before Michela, deflecting the blast in the nick of time.

Introducing himself as Eusius, the young man tells of a foreboding tale: that he has come from the future to save her... and that she’s fated to die at the young age of 18......

The world's strongest white dragon... becomes the tyrant's wife?

Betrayed by her only friend, she is given a new lease on life reborn as the daughter of the knight who killed her. How will she take her revenge on those who have wronged her?

From NOIR:
Yuri is a doll-like child, orphaned at a young age when her mother dies in a car accident. In her will, she requests that Yuri be placed under the guardianship of a close friend of hers, Kim Dowook. Taken in, Yuri begins a new life, different from her life before. Where will this take her, and what does she think of her guardian..?

Meng Geum Ho, who is actually the popular author Eun Ho, transfers to a new school. Unwilling to socialize with any of his classmates, he soon gets himself a bad reputation as someone who is not to mess with. When the unpopular girl called "One" accidentally watches him beat up some guys, she runs away in fear but leaves her lunchbox behind. Meng Geum Ho finds it and searches for its owner stating that he also have a request for that person.
What could that request be? And what happens when One and Meng Geum Ho are forced to be partners on a field trip?

I was studying for a test, slowly succumbing to the lull of sleep, when my eyes fluttered shut... And the next thing I knew, I had tripped into another world——

I found myself in a remote village in the countryside, Thrall Village. From being taken in by the village chief as his adopted daughter, to learning about the country and its language, my leisurely life there had begun. In this manner, six years quietly flew by.

But one day, I was suddenly summoned to the royal capital to become a priest’s secretary!? Moreover, I received an important task — to find a bride for the Archbishop!

From Chibi Manga:
I thought I didn't need something like or love. I'm small, and I have a height complex. I am Koeda Tsugumi (First year High). One day, Sena Masamune from the next class, saw my body by coincident...!? But, after finding out, I was always with him and he hid my secret that I'm actually a girl, and slowly my feelings grow....A useless girl in love, a pure slow love!

Alternate:
Short skinny girl living her life with no thoughts of love, until one day popular hot guy sees her exposed rib cage on accident. Self conscious she leaves the room dropping a hairpin the process. Hot guy picks it up, and returns it to her. This signals the start of something more?

Serina arrives at school one day to discover her desk has been vandalized—someone's scratched the lyrics to a love song on it...and that someone turns out to be Mizukawa-senpai, a boy who's one year her senior. She wants to get to know him better, but if his frosty demeanor is any indication, she doesn't have a chance! But it seems he might be awkward—not simply mean—and before she knows it, she's asking him out...! With each passing day, her heart races a little faster!

Ran is always called the Takane no Hana because she stands out. And her classmate, Akira, approaches her normally...!? Takane girl x flower shop boy's first love story is beginning!

From Lovesick Alley and Sunday Scans:

Tsubomi is in her second year of high school and has a crush on her homeroom teacher. She plans to give her teacher a birthday gift, but unfortunately his birthday falls on a weekend... After finding out that her classmate Fuma Yabuki is her teacher's cousin, she tried to get him to help her but despite being related to her homeroom teacher, who is nice and warm, Fuma is very standoffish and doesn't want to help her out. Will this be the start or the end of Tsubomi's love?

The protagonist lives and works in a boarding house and has a phobia of boys, however she finds herself having to manage her fear when two new boys are hired in the boarding house who will live and work there. One is a silent boy who confesses he hates girls, the other is a school friend who can't stand the protagonist because of her elusive character...

Kang Ha Ji was a lovable, friendly girl who fell victim of bullying by the school's most popular girl because of her childhood friend Hong Min-Joo. Then one rainy day after an attempt to save a black cat from jumping into the road. She fell through a dimension crack and was transported to Cat's Kingdom.
"Did I found myself in a situation that's waaaay over my head because I met the Prince of this Kingdom?"

Fantasy Romance manhwa of an adorable cat's Bride.

From CoyoMoose & Turtle Paradise:

Third-year high school student Tachibana Kyou's world is shaken when a green-horn nurse suddenly arrives at his exclusively male school - the doe-eyed, baby-faced, and irresistably adorable Hirota Natsu. Completely taken with the new faculty member, Kyou abandons his playboy lifestyle for her, having found true love for the first time... But what will fate have in store for these two, engaged in the taboo relationship between teacher and pupil...!?

This is an adaptation of the Mirage of Blaze novel, and so far seems to follow the original source material closely.

The complex plot incorporates a large number of elements - including romantic melodrama, historical politics and supernatural fantasy. Japanese history predominates the heavily structured story-line, which mainly involves the continued aggression between power-wielding guardians ('possessors'), and the denizens of a 'feudal underworld'- a group of restless souls belonging to long-dead samurai from the Sengoku era who are attempting to re-ignite those age-old wars in present-day Japan.

Once upon a time there was a wonderful prince… A super rich and handsome prince with a genius IQ of 500, extraordinary physical prowess… An outrageously overpowered super star…!! What will happen when this ridiculously overpowered ultra-high spec boy and a certain ultra-level-headed ordinary girl meet…?!

17-year-old highschool student Rise is going out with her childhood friend Hiroomi, a young lawyer. Because of the age gap, Hiroomi imposes the condition that they do not have sexual contact until her graduation, however, Rise doesn't want to wait until then...

During the high school entrance ceremony, Koga Eito from the special class helps Kasuga Niina from her poor health. His gentle manner captivates Niina, making her confess her feeling towards him. Thus, the trials in love of this couple begin.
As time passes, Niina finds it difficult to continue loving him since there are instances when he seems to be playing with her feelings. For her, going out with Koga may bring a grim future to her.

The spam-mail boom of the near future: The great advances of technology, a new generation of improved systems, and ideal computer programs have caused a backlash. The IT world has advanced significantly to the point where humanoid "Spam" mails are causing trouble for their humans. In the near future, hundreds of thousands of spammers have caused incalculable destruction to the mainframe of the lives of everyday citizens. Enter "SM" Hunters to save the humans from our own creations. Can "Spam" ever be good?

From Udon Entertainment:

The Grim Peddler waltzes through fairy tales, giving the stories' inhabitants their hearts' desires. But benefactors beware, for his gifts don't always turn out quite as expected! Classic fables like Sleeping Beauty, Hansel and Gretel, The Frog Prince and more are turned on their side through the unexpected reversals and terrifying twists of this all-new series.

From StarryHeaven:

I’m Anna. I’m 14 years old and I’ve just entered the ninth grade. Sou and Hinata, who live in the same apartment complex as me, are my childhood friends and we’re all the same age. I thought that from now on we’d become even closer friends, but then Sou suddenly did that to me…!!