Fifteen years ago, natality decreased greatly in Japan and the few who were born during that time are called the "Old Generation" or "Oldgens."
Hanasaka Haru, a 15-year-old Oldgen, has never met any classmates before. Now, he goes to school for the first time and meets Himeshiro Sakurako. But Sakurako is not quite the ideal classmate he imagined, and his dream school life isn't turning out the way he wanted it to...

Takeo, the most unfortunate girl in the universe, pulls on her usual protective gear and goes to her first day at her new school. Having decided to give her parents some relief by living on her own, she ends up, due to a per-usually unfortunate housing mix-up, moving into an inn called Hyakkisou (the Manor of 100 Demons). The life of the young Takeo—or is it Take-woe?—will begin to change the day she sees the youkai... and vice versa.

Affectionately set in an everyday modern Japan with a Hellish war lurking in the background and high-school acceptance issues in the fore, the characters, setting, art and plot all make this story well worth crossing the threshold of Hyakkisou!

The Day To Day Life of Magical Girl and The Right Hand-Man of an Evil Empire.

Fujiwara-sensei passed away suddenly, leaving this manga incomplete. The latest chapter is completed on March 20th, 2015.

Rest in peace, Sensei.

[Summary by OSTNT] In a world of martial arts, a young boy named Wu was unable to practice martial arts due to his special body. Will he accept his fate and live his life bullied and looked down by others, or will he rise and become a master?

Ellios, fiancée of the powerful man of the city, Samos, ran away to Athens with her true love, Frontis. Therefore, the powerful man of Samos, Yadmon, brought his soldiers to Athens to kill Ellios and Frontis where they were hiding, and takes Aesop, their son, for his slave.

From LINE Webtoon:
You know his fables, but do you know his story? Yangsoo Kim and Dogado imagine Aesop's early life as a slave in Ancient Greece. He becomes a prisoner after his parents' love draws the ire of a powerful ruler. And that is only the beginning.

After the assassination of the powerful Godfather, Don Pazolini, the world has been thrown into chaos. Many mafia try to fill the power vacuum, but there is a rumor that Don Pazolini's son is hidden away somewhere. That son is Nero, an orphan who is raised in a bar with showgirls as his friends. He dreams of one day finding his parents, but he doesn't know who they are. One day, he encounters a haunted baseball bat, who names himself "Pucchi" and refers to himself as the Pazolini family 'fantasma.' Pucchi insists that Nero come with him to become the new Godfather and rebuild the Pazolini mafia family. Nero is reluctant, but quickly realizes he has no choice, since there is a price on his head and his identity is no longer much of a secret.

Plot revolves around high school freshman Shingo Susa as he is invited by his crush from middle school Sayuri Shiroyuki to the school's supernatural club. Over the course of the series Susa begins to gain supernatural powers, something that prodigy Rei Uryu, attempts to awaken to bring out the psychic giant, Susano Oh to destroy humanity and establish a new world order.

Won the 4th Kodansha Manga Award for Shounen in 1980.

From MangaHelpers:

Takahashi Ena is a high-school idol with a secret hobby. She often wears headphones, and people assume she is listening to music. In actuality, there is no music playing; she is eavesdropping! She prefers to listen to two of her male classmates, Nara and Mikage, because they have the most interesting conversations. She has to be careful to not be found out, though, because a creepy hobby like that could ruin her image! [tethysdust]

Accompanied by a talking lantern, Mika pursues her sister on a quest to retrieve that which was stolen from her long ago.

N/A

A story about a boy who is able to talk to the Gods.

Since the beginning of time ninjas have been regarded as people with great skill and power, the Blazing NinjaMan (Shinobi Mantaro) is one such young man. There is only one problem, the era of the ninja has come and gone. How can Shinobi consider himself a ninja in modern day Japan (1990s) and survive the daily rigors of high school life.

From MangaHelpers:
Yasaka Tokiwa lives in an unusual time, and according to his dreams, it's about to become even stranger. He's been having a dream of a woman called Ri'in ever since the robot, who he calls Makina, came to his home. He and Makina attend the same school, where their other classmates include a secret ninja (Kusanagi Kanata) and a sorcerer (Yata Haruka).
When Tokiwa, the robot, the ninja, and the sorcerer rush to rescue the student council president from a demon, the boys find that they've all been having the same dream! What is going to happen to their world?

Who do you think lives next door? A college student?
A secretary? A foodie? A quiet sort?
Or a killer?

Humanity's peaceful days all at once transform into an unspeakably odious hell.
The sudden invasion of wasp-like insects, along with gargantuan "dolls" wielding their enormous alien weapons, annihilating everyone in their path.
In the middle of the chaos, high school first-year, Iruma Ikaruga, fights to save his best friend and his beloved senpai from the dolls' assault with an unyielding spirit.
However, all that awaits him is despair.
Just what are the enormous puppets known as "Dolly"after?
What fate awaits Iruma?
The curtain has risen on humanity's "puppet show" of unimaginable despair, and the battle for survival has begun.

From Kodansha:

Class troublemaker Ryu Yamada is already having a bad day when he stumbles down a staircase along with star student Urara Shiraishi. When he wakes up, he realizes they have switched bodies—and that Ryu has the power to trade places with anyone just by kissing them! After figuring out the workings behind this new and amazing ability, Ryu and Urara take full advantage of the situation to improve their lives. But with such an oddly amazing power, just how long will Ryu and Urara be able to keep their secret under wraps?

One social outcast unleashes a cross counter that will change the world! A raging storm of fighting action!

Shotaro Mitarai has given up on life, but when he visits the great forests of Mt. Fuji to end it all, he's attacked by the Suicide Hunters. On the tip of a gruesome lynching and faced with a tragic death, the seeds of rage sprout within Shotaro! What course of action will he take from within the inferno of anger?!

Awaken! Stand and fight! Let the gong of your soul sound true!

The spin-off of the popular fantasy manga "Fairy Tail". Consists of 3 volumes

Volume 1: Kengami no Souryuu / Twin Dragons of Sabertooth
Sting, who became the master of Sabertooth, Rogue, Yukino, and Minerva together perform jobs together, but...? What is the danger approaching their guild and the whole continent!? The episode that was not shown in the original story is now being told!!

Volume 2: Rhodonite / Road Knight
Spin-off of Fairy Tail following Gajeel and his past.

Volume 3: Raigo Issen / Flash of Great Lightning
The story centers Laxus Dreyar, the Thunder God Tribe, and the time they were affiliated with Blue Pegasus.

A story about a long-necked girl's love life:
Kanoi Natsuki and her childhood friend Itsuki visit the same school and there seems to be more between them besides friendship. As a Rokurokubi, her quirk of stretching her neck is normal for her and her surroundings, but it's not always her choice to stretch it and although she has feelings for Itsuki, she can't tell him what she feels. Ultimately, she has to go through misunderstandings and shame.
Itsuki, meanwhile, manages to make any awkward situations dissolve or maybe not?

From Manga Box:
One day, a yakuza gang member is attacked in Roppongi, Tokyo. This is only a prologue to one man's revenge story, triggered by the events of twenty-two years ago. The flames of revenge burn in the darkness of the city. By the author of Hitoshi Tadano, Chief of Special Operations, Kimio Yanagizawa.