From Aerandria Scans:

His highness the prince of Estolia Wilfred became an exchange student in Eito University. His noble appearance and gentleman’s manners quickly filled the campus with hysterical women’s voices. Miyako also studies at that university and for her master’s thesis, she is determined to interview the prince about his great-grandmother. But when she approaches him about it, she suddenly discovers “the dark side” of his character...?!

Contains Oneshot: Sinful Love ~ Your Future is Mine
Sequel of A Sin to Love You and A Sin to Love You~Can't Live witout You~ from Fu Junai

Takaki loves ranking the popular and beautiful girls at his school. The one standing at the top is the foreign transfer student Emilia Shutrause, and being a student from Europe, she is extremely popular among the male students at Takaki’s high school. Although he was just a spectator of this school idol, that would change when one day he accidentally bumps into Emily (Emilia’s nickname) and he finds out her secret...

From Viz:
Ryoma Echizen just joined the Seishun Academy's tennis team, which is known for being one of the most competitive teams in Japan. Its members are incredibly talented, gifted, and athletic. With rigorous and extremely intense practices, the upperclassmen of the team expect the very best from themselves and they expect even more from the new members of the team. While most of the freshmen are on pins and needles hoping they won't get cut from the team, Ryoma Echizen is confident, cool, and collected. Some might even say he's cocky, but at least he's got the skills to back up his attitude. With his virtually unreturnable "twist serve," Ryoma is sure to make the starting team.
Join Ryoma and the other first years, as they train hard, make friends, and try to find a place for themselves on the team. And meet Ryoma's cute but chronically shy classmate Sakuno Ryuzaki. She's got a big crush on Ryoma, but will he ever notice her? Ryoma Echizen is the Prince of Tennis. He may be ready for the Seishun Academy tennis team, but are they ready for him?

One rainy night, Wada, a young teenage boy, standing near the edge of a bridge over a raging river - is on a depressing brink towards committing suicide. Suddenly, a beautiful blonde foreign girl, named Lisa, mysteriously appears. Who is this cheerful girl? And why is she dressed as a cheerleader? Wada wasn't interested and tries to ignore her, but Lisa kicks him off the bridge, and says "try flying." And to his surprise, he does. This power, where did it come from?

It seems that there is a war between the gods and demons. And by fate, the result of this war is tied to Wada. Upon learning this, Wada does not look very pleased. Was this his purpose - his destiny? What will he choose? Does he even have a choice? Afterall, Lisa, the goddess cheering him on, is surprisingly his classmate.

Haunted by a space flight accident that claimed the life of his beloved wife, Yuri finds himself six years later as part of a team of debris cleaners on a vessel called the Toy Box charged with clearing space junk from space flight paths. The team consists of Hachimaki, a hot shot debris-man with a sailor's affinity for the orbital ocean; Fee, a chain-smoking tomboy beauty with an abrasive edge; and Pops, a veteran orbital mechanic whose avuncular presence soothes the stress of the job.

Note: Won the Seiun Award in 2002.

From HMR:

The main character, Rui, is a hardworking and happy girl. One day, her neighbor moves away and leaves behind a stuffed panda bear. Rui decided to take it home, since she's always loved panda bears. She goes to sleep with it one night, and discovers herself in bed with a stranger (who also happens to look like her ideal man) the next morning. He introduces himself as Peter, and that is how she ends up meeting three other guys...

An older brother discovered his interest in cross-dressing and totally grossed out his sister. After consulting online message board, he decided he will play the role of older sister instead to build better relationship with her.

Sixteen-year-old Nene Kashiwagi has undergone a transformation from a sporty girl to a chic one--or, at least, she's trying to become chic so that she can finally find love! Her efforts only gain her teasing from her (former) friend, Jun Endou. But when Nene's first attempt at finding love goes awry, Jun steps in to rescue her in the most unexpected way.

Iroha, a masculine girl, and Hifumi, a feminine boy, are siblings who have transferred to a different middle school and moved to their grandparents house. However, after the first night, much to their surprise... they've switched genders. The two are left feeling "delighted"...

Danjou Yamato is a high-school student who lives in the countryside and is the boxing champion of the region. However, when his family has to move out to live in Tokyo, he is transfered to a school in Tokyo that was previously an all-girls school. Girls have a lot of power and give the guys a hard time. But Yamato will not bow down to the power of the girls, and on his way to claim power for the guys in the school, he finds out something about his past... something that he had forgotten long ago...

From Chibi Manga:

The eldest son, Yukiya is a man who wears glasses and has gentle manners, but is a SM fiction writer. The second son, Kousuke, is a handsome youth with a childlike face, but he is the number 1 host. The third son, Masaki is an extremely popular idol, but he is ill mannered and like to tease everyone…and these three older brothers dote the youngest child, Miyuki with excessive care. Trying to escape from their constant interference she creates a plan but…!?

Story 2:
Strong way romantica
about a priest sensei and a 2nd year student responsible for school regulation reinforcement.

Story 3:
Please teach me, School President!

Weak, bullied, and pessimistic about life, that's Setsuna Kashiwagi. On the verge of jumping off a bridge, a mysterious man appears behind him and offers the contract "10 million yen in exchange for your life in a year." Skeptical at first, he accepts. Waking up the next morning, thinking it was just a dream, he notices 2 beautiful women sitting beside him. They are Kanna and Rena, Oni princesses here to claim his heart in a year.

From: Easy Going Scans

Pinocchio prequel ~ This little series tells the story of the 1st winter Ga On became a ghost.

From Turtle Paradise:

Iwakura Matsuri is a shrine maiden at her family’s temple, the Iwakura Shrine, where day after day she creates Omamori after Omamori, each one reputed to be uncommonly potent when it comes to fulfilling their possessors’ wishes… A fact that she doesn’t buy into one bit. But imagine her surprise when one day a small boy suddenly emerges from her own omamori which her parents left her before they died! His name is Mimori, and he claims to be one of the gods who dwell inside each and every omamori…

Together, Matsuri and Mimori learn more about love, devotion, friendship, and each other as they encounter more Omamori in their everyday lives.

Sequel of Beach Stars, the story begins where it stopped in the first one.
Nanase, who's now the representative of her prefecture, has finally joined the Madonna Cup and will do everything in her power to defeat her one and only target: Hayakawa Sanae!

Sakura Hayato is a normal high school student - except for the fact that he is abnormally popular with ghosts, which is quite frankly a pain in the neck to him. Just then, he meets the -Undertaker-, who claims his duty is to send off spirits to the other world... This is the oneshot version of -Undertaker Riddle- which is currently being serialised in GanGan Online.

From RC-SCANS:

Gook Eun-Song is your average high school girl... that is until her attractive younger sister stole the man she had a crush on. Depressed, Eun-Song purchased a bottle of alcohol and crawled into a supposedly cursed closet in her father's furniture store.
Yu Ha is your average typical bad boy. Going insane over one article in magazine, he even broke traffic regulations while drunk just to end up being chased by a couple of police officers.

Oddly enough, he also ended up in the same closet where Eun-Song is asleep from drinking too much. Yu Ha ends up sleeping in the cursed closet with Eun-Song by his side... just to find out the next day, their bodies have been switched!

Can anything else possibly go wrong for our poor heroine?

STYLISH ACTION FROM THE AUTHOR OF ARCHLORD! The new English teacher, Chun-Woo, is not your ordinary teacher. Shioon, a victim of constant bullying, unexpectedly witnesses Chun-Woo's fighting power, and begs him to make him his disciple. Chun-Woo claims he can teach Shioon only if he is truly determined, and Shioon must jump off a bridge into a deep river in order to prove it! It turns out, however, that Chun-Woo and his powers are more than meets the eye. Shioon makes a grand entrance into the hidden world of martial arts, and he is about to be taught by the best there is! You can read part 2: The Breaker - New Waves here.

Manhwa you may like:
+ The Gamer - ​THE 게이머
+ Gosu 고수
+ Yongbi The Invincible 용비불패

Transfer student Manabizaki Kyou is a swot, a person who spends too much time studying. His dream is to attend Tokyo University and then work for NASA! He will soon discover, however, that the high school he's transferred into, which was once very prestigious, has taken in delinquents from the surrounding schools. Now it is full of violence and gang fights.
Luckily, Manabizaki has a surprising skill at fighting, particularly when he's defending the peace of his study area. Through this strength he'll find his new friends, a weak boy called Iwashida and a legendary delinquent girl, Hasuno Nene, who makes him feel things that, for the first time in his life, he can't explain...

The demon queen subdued enormous and powerful monsters and slaughtered over half of the world's population. Surviving members of the human race elected a hero to slay the demon queen, beseeching release from her oppressive rule. However, he questions his mission to eradicate the monsters: in his opinion, they too are conscious and alive, and so he anguishes over that fact. Sheila the Demon Queen became interested in him and decides to join his journey, hiding her identity and planning to kill him after she has gained his trust. Immediately, however, she realizes that she's fallen in love with the hero, and hence their journey begins...