From Simple Scans:
In the Spring she was 16, Takamiya Naho receives a strange, but detailed letter from herself, ten years in the future. At first she thinks the letter is a prank, but then the things written in the letter actually happen, including the new transfer student that sits next to her in class, Naruse Kakeru. The letter reads just like her diary entries, down to the same characters. It is not till two weeks later, when Kakeru shows back up at school, that Naho finishes the letter. In the letter, her 27-year-old self tells her 16-year-old self that her biggest regret is that Kakeru is no longer with them in the future, and asks her to watch him closely.

Note: Was nominated for the 20th Tezuka Osamu Cultural Prize in 2016.

A reincarnator, Dahliya, taking advantage of her broken engagement, “I won't hang my head any longer” made firm her resolve.

Now using her beloved magic devices any way she wishes, the fun times keep rolling in ―?!

The story centers on a romance story about a person who can't be upfront about their feelings.

Kiryuuin Kirari, a rich young lady who doesn't know anything of the world, is introduced by her mother to the historic Meisou Bookstore, which will be the setting of her first part time job experience. It turns out the Meisou Bookstore is in fact filled with anime goods, doujinshis and idol lives, a true otaku bookstore!

Just when Hyuuma Tadahito had finally received a job offer from a publisher, he was hit by a truck. But when he woke up, he was in a publishing company in a world where he was the only human! Now he will have to get used to his new working life in another world...!

A scary stalker is after me!!!! What could be his ulterior motive?

Six months after the world ended, a young man continues to live with his manager at a shopping mall. The rest had left, believing a rumor of salvation if they manage to reach the centre.

During one of his rounds, he finds the first living person he's seen in a while. The girl who introduced herself as "Romero", was roaming not for food, water, or salvation—but rather, for a movie...?! "Who cares about humanity! The world is already up in flames, so why not just kick back and watch a movie?"

An up-and-coming author's exhilarating debut work! Nothing beats watching a flick during the end of the world!

When evil aliens arrive on Earth, seeking its destruction, it’s up to the planet’s kaiju monsters to save the day! But things aren’t exactly as you’d expect… These kaiju may be adorable young women, but they’re no less ready to kick some alien butt!

Lin Tian-Yu is the president of the student council and the disciplinary committee, and Xu Ze is a high school freshman. During a regular classroom inspection, Tian-Yu finds Xu Ze sleeping during morning self-study and reprimands him. Their seemingly ordinary encounter ends up changing the lives of the two greatly as they grow closer despite their apparent differences.

Saotome secretely loves Moe idols even though she is a gal(Japanese term for popular girls). Otonashi is what you would consider Otaku(nerd) that also has a secret.

Chiharu and Maki have worked at the same company together for three years. They were both unceremoniously dumped this spring. As they got drunk together one night, they were both summoned to another world. They were given the very simple job of cleansing miasma.
Well, they had no choice now. They will drink and eat, and if possible, search for a boyfriend who wouldn’t cheat on them.
This is the beginning of their aimless journey through another world.

Eishi Karasuma is a loner with a monotone life and his only friend is Mikisada Kamoda. One day they venture together while skipping class and they meet Tsubame, a very energetic girl, and Rei Sagisawa, a pretty boy that attends the same middle school. On their way back to school a sudden event happens. A mysterious boy with wings will come to help.

Momoe Nami has only just become a high schooler, yet she has become a shut-in from getting haunted by a Gashadokuro (giant skeleton youkai). I'm going to fall head over heels for Mr. Skeleton!?

A comedy featuring a non-human x young girl pairing!

"…That person, my fated one."

Everything changed for Berlina, a girl who reincarnated in a fantasy world with memories of her previous life, the moment she laid eyes on the Hero, Chris. She abandoned her life in the city and started a new life of chasing after him! Whether in fire, water, or inside a dangerous dungeon, firmly hiding 10 meters behind the figure of the Hero, to chase and watch over him. All to be his bride!!

Mizuki and Kazuya, childhood friends, are 3 years apart.
It's not really a so-called "Age Gap" but that makes some distance between them during their youth.
From their childhoold to the present, story will be told about these two who are 3 years apart.

Links:
Artist’s Pixiv: https://www.pixiv.net/member.php?id=596062
Artist’s Twitter: https://twitter.com/shimazakikazumi

From Etc:
Dr. Katou is an ambitious woman who seeks to revolutionize the corrupt and inefficient Japanese medical system from within by becoming a professor in a teaching hospital. She enlists a maverick surgeon, Dr. Asada Ryuutarou, to help her with research that would catapult her to a professorship should they succeed and publish. However, Asada's refusal to conform to the system soon threatens to destroy not only her plans but her entire career. Katou is prepared to do anything, including going along with the system, in order to achieve her end goal, but she begins to question whether she has gone too far as Asada's actions bring many of the system's shortcomings to light.

Note: Won the 50th Shogakukan Manga Award for general manga in 2005.

Xiao Man, the beloved heir to the north area's martial arts club, suddenly decides to transfer to a south area high school to pursue "him". However, on her first day as a transfer student, everyone –including the teachers– mistakes her for a male delinquent. How will she get the boy she likes to see her as a love interest instead of a "buddy"? Adventure into the life of Xiao Man!

Unoki-kun, a boy who's been bullied since elementary school, ends up becoming the exclusive errand boy of the top delinquent of his school, Toramaru-san, who told him "Be mine" right after entering high school. But the truth is that Toramaru-san meant it as a confession of love!! This is the beginning of a love misunderstanding between Toramaru-san who thinks she's in a relationship and the beta Unoki who think he's being bullied.

To help with his family finances, Higashida Daisuke decided to work part-time at a family restaurant. Working there however is a chef with no sense of cooking, a co-worker who solves their problems with money, etc. There is absolutely not one normal person working at the restaurant!

A retired man faced with his own mortality at a friend's funeral decides to start ballet. Recommended by Kim Tae Hyung ssi (BTS).