From Broccoli:
Princess Alita must protect her kingdom from a coup d'etat. But on her way to get help, a magical mishap trapped her inside the body of a bounty hunter named Falis. Now Alita must rule disguised as a servant as the battle-savvy Falis sits on the throne in her body.

And thus the story about the strongest and most violent princess in the history of the kingdom begins.

Reincarnated to a werewolf magician, the Protagonist Vyett was instated as the vice head of the Demon Lord's third brigade force. Occupying a remote market town, he was entrusted to management and defense.

"As a former human, born a monster, I can understand the sentiments of both sides well enough. Because of that, those around seem to think I'm a man of wisdom, or something of the like, but it's really just one trouble after the next. I have to follow those monsters that are overly quick to resort to violence, and do something about the humans, who start to complain immediately. So today as well, I'll do my best at managing the Demon Lord's main force."

Official manga page

The great demon Mao Dante, exploiting the weakness of a boy exposed to his demonic influence in his dreams, is awakened from a thousand-year sleep. The intent of this being, a survivor of an ancient and forgotten civilization, is to wipe out the whole human race.
But it's not that simple: the motivations of the demon aren't so wicked as one might think, and they will combine with the life of the boy, which hangs between nightmares and craziness. In the meanwhile, the Satanists fight against the hierarchy of the church to obtain a justice which is, as it's easy to guess, that of the demon Mao.

This series didn't have an ending until its remake in 2002. Nagai took many ideas from Mao Dante into Devilman.

[It’s a familiar dungeon.]
Inside a medium-boss room of an RPG game that he played again and again until he can get there with his eyes closed.

Waiting for a hero, a demon who exists only to be defeated, got his former life memory revived.

Knowing that, in his previous life, he was a nothing-special college student-

Continuing to stay as a to-be-defeated mid-boss is a no.

The determined him, decided to defeat the boss and escape the dungeon.

That which was obtained in the process was a doping item called “pearl piece”.(Jap:”珠片”) The demon, who was ordered by the goddess to collect the 15 pearl pieces that was scattered around the world, decided that after all this, he at least want to travel around the world of his favorite RPG game. This would one day become the legend of the Demon God of Oeyama, the demon romance story.

When the looming Cold War shrouded Japan, mysterious murders were reported there. The suspect was a man with a skull-like helmet and a cape and clothing as black as the inside of a grave.

Accompanied by a shape-shifting beast named Garo, the Skull Man terrified Japanese society—without giving the people a clear reason why.

In the panic surrounding a worldwide pandemic which kills 15 percent of the population and cripples many more, a secret organization, the Propater, topples the UN and seizes control of much of the world. A boy and a girl, raised in an abandoned virology research center, immune to the virus, are attacked by the Propater and escape.

Based strongly on Gnostic mythology, all major characters are named after gnostic deities, and have analogous roles.

Nana, an apathetic 24-year-old with nothing much in her life, suffers a car accident and wakes up in her 14-year-old junior high body. As she lives through each day, she starts to remember things she buried deep in her memory, and she can now not remember being involved with her older sister, whom she deeply admires, and her sister's first love, a senior at her school.

"Jesus. Teacher, healer, savior. The story of one of the most revered figures in human history is revisited in this full-length graphic novel, featuring breathtaking full-color art by Yoshikazu Yasuhiko, the creator of ""Joan."" This faithful adaptation of the New Testament text follows Jesus from his days at Calvary to the time of the Crucifixion and beyond. "

Because she killed herself, Sagiri became one who escorts souls of those who have died, instead of going to heaven. She met Hisagi while he was crossing the river of the world of the dead... They promised they would meet again and live happily in their next lives... Can their promise be fulfilled?

The year is Universal Century 0096, and Banagher Links is a student at the Anaheim Electronics Industrial College training facility at an incomplete space colony. There, he rescues a girl named Audrey Burne and helps her to evade capture by Zeon remnants known as the Sleeves. The Sleeves are after "Laplace's Box" an item the Vist Foundation has had in its possession since the beginning of the Universal Century which can be used to topple the Earth Federation government, and Cardeas Vist, the head of the family plans to hand them the key to it. Audrey, fearful of what will happen, wants to convince Vist not to give them the key. The Earth Federation's Londo Bell unit attacks the Sleeves and Banagher is drawn into the chaos. Adapted from the light novel series that were later adapted into a feature film series, the first of which has already been released this February 2010.

From Kotonoha:
Based on the award-winning novel by Shinji Kajio, Memories of Emanon tells the story of a mysterious girl who holds a 3-billion-year old memory, dating back to the moment life first appeared on Earth.

Kuro-chan is a loyal watch cat who guards his elderly owners with love and affection from thieves and "yaggs". One day while trying to visit his crush (a female dog named Pooly), he and Pooly are attacked by a mad scientist. Turned into a cyborg by the scientist, can Kuro-chan escape Pooly and return to his loyal masters?

When forcibly injected with the DNA of Musashi—the legendary swordsman—by the secret organization Akai Umi (Red Sea), Hagane Yakushimaru becomes a master fencer with supernatural powers. She sets off to rescue her parents, who have been abducted by Akai Umi, making friends and foes with supernatural beings (parasite projects) who have also been injected with the DNA of other historical figures.

What is Hagane's secret? Why is she the only successful female DNA injection recipient? What exactly is the project called the "Revelations of the New Millennium"? A veteran artist depicts a futuristic battle manga on a grand scale.

As a baby Jiro was delivered to his foster parents by a massive oni, who said he would return for Jiro in 15 years. When the time comes Jiro must contend with enemy oni, dark cultists, and their minions while attempting to protect both his parents and girlfriend from their depredations. Ultimately he must embark on a journey through the past, future, and other dimensions to embrace his destiny as Shuten Doji reborn.

That day, I died at the train station and my mind got transferred inside to a body of a girl in a fantasy world.

Haotian and the Emperor's third son, Liu Xi, were rivals. One day, they quarrelled with each other and unfortunately both of them fell into the Otome Reincarnation Road and being reincarnated into pretty girls.

Fourteen-year-old Kouichi Hayase’s life has always been a mediocre one, if not dismal. However, those days of being bullied by classmates and escaping to a fantasy of being a hero are put to an end when a certain “accident” bestows on him a girl and a gigantic humanoid robot called “LINEBARREL”. The extraordinary power that Kouichi obtains puts him and everything around him on a sudden rollercoaster ride of battles, intrigues and friendship! During the course of his adventure, the boy starts to learn what life has to offer; he meets new friends, bids farewell to the old ones, but most of all he now has considerable responsibilities and is forced to confront the world around him.

One of Go Nagai's first works, this violent period piece takes place in the 1500s and stars a talented, low-ranking ninja named Shishimaru. In it, Shishimaru fights against Ginnai Doma (an immortal samurai who, despite being butchered multiple times, doesn't die) because Ginnai murdered his comrades.

Despite being set in historical times, it has time travel, aliens and the alternate universe war.

From Dazzling Scans:

When the masculine and popular-with-the-ladies Ooji Subaru arrives at her new school, her encounter with her childhood friend Megumi and the other four “princes” of the school leads to the discovery of her past life. She is the reincarnated Prince Charming, who was a womanizer who seduced all of the princesses in the land. As a result, a jealous witch placed a curse on him and doomed him to be reincarnated as a woman for eternity. In order to break the spell, Subaru must find the “princess”—now reincarnated as men—who is her one true love!

Fudou Jun is a highschool teacher and takes a trip with a group of students. While there, a group of martial artists staying nearby take a strange interest in the girls.
These men are actually demons and after changing into their true form break into the cabin to rape the girls. One gets Jun and violates her.
She feels her soul being torn apart and transforms into Devilman Lady. With newfound powers and strength she kills all the demons and protects the girls from any further harm.
What are these demons and why did she turn into a hybrid of one? What does this mean for her and for the rest of humanity?