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?

Fear runs rampant throughout Tokyo with the revelation that demons in fact exist amongst us. Paranoia and the darker side of humanity boils onto the streets as people turn on one another, suspecting that anyone could in fact be a demon hiding in human clothing. Amidst the growing tensions, tragedy strikes Akira causing his mind to snap, retreating into his subconscious, allowing his Devilish alter-ego Amon to break free from Akira's cage of flesh and wreak havoc on both human and demons alike.

Keidai Saeki is a high school student who remembers his past life in Pompeii, living as the Italian warrior Sirix. His friends around him are all also reincarnated - although they don't quite remember things the way he does. Keidai's wife from the past? She's now a middle school boy - while his best male friend is now a cute girl?! Throw in a case of love at first sight, and you have a new look at romance - manga-style!

From Impossibility:

Morisawa Kai and Sato Tatsuki are best friends. However, unlike Kai, Tatsuki is completely unreliable, lazy, and ill-tempered. One day Tatsuki takes Kai out driving in his new motocycle only to get into a bad accident that leaves Kai dead. However, Kai's spirit ends up in a body of a girl named Fujii Marika. After seeing how cold and unaffected Tatsuki as well as everyone else was after his death, Kai transfers to his previous school in which he starts noticing flaws to Tatsuki's cool mask...

From Tokyopop:

Guilt-Na-Zan is a vampire aristocrat who was sealed into a cross by Kyouji's ancestor more than 100 years ago. Now Kyouji has revived him--although his soul was resurrected into a cute female doll and can only transform into his real figure when he sucks blood from Kyouji's sister Tonae. But when you combine Goth clothes and hot vampires, slowly but surely everyone will start to feel like one big family!

One day, suddenly... a night where the moon shines like never before, a boy meets the otherworldly Serin, a denizen of Chaos, only to die and become the undead. Now immortal, he can no longer exist with humans due to an ancient law... A tale of revelations that begins as he returns to Chaos, the start of a new adventure!

Although a 19th-century philosopher once said that "God is dead" (It was Nietzsche) the Rakia story has God descending to Earth in the 21st century and assuming the form of a girl. ("Rakia" is the Hebrew word for the skies or the firmament.)

From Yen Press:
The air of celebration surrounding fifteen-year-old Oz Vessalius’s coming-of-age ceremony quickly turns to horror when he is condemned for a sin about which he knows nothing. He is thrown into an eternal prison known as the Abyss, from which there is no escape. There, he meets a young girl named Alice, who is not what she seems. Now that the relentless cogs of fate have begun to turn, will they lead only to crushing despair for Oz, or is there some shred of hope for him to grasp on to?

It centers around the travels and battles of one Aotsuki Ushio, who is constantly being stalked and aided by a gigantic, supernatural and sometimes invisible tiger (Some people describe it as akin to Calvin and Hobbes on acid).

Ushio's family maintains a Shinto temple in Japan, where 500 years ago, his samurai ancestor battled that same tiger to a standstill, and eventually trapped him against a rock using, a blessed spear called the "Beast Spear", which in addition to its intrinsic formidability as a weapon, can also boost the physical powers of the user. While cleaning out the temple storage, Ushio accidentally unseals the chamber which Tora was trapped in. Initially, Ushio wisely refused to remove the spear pinning Tora (とら, Japanese for tiger) down, as Tora unwisely makes the strategic blunder of mentioning that the first thing he would do upon being freed would be to devour Ushio; but Tora's unsealed presence attracts various demons to the premises, and Ushio is forced to free Tora in exchange for his help. The series focuses on their relationship, interspersed with battles against mythological foes, and with Tora's attempts to grapple with modern life and gobble up Ushio.

Won the Seiun Award for Best Comic of the Year in 1997. It also received the Shogakukan Manga Award for shounen in 1992.

The Sleepless King summons young ladies to the palace every night and make them tell him bedtime stories, and the penalty for failing to lull him to sleep is death. The one who finally managed to sooth the king to sleep is Lady Farasha, who volunteered as the storyteller in order to save her imprisoned father. But how was she able to accomplish the impossible? Is there more to the relationship between the Sleepless King and Lady Farasha than what meets the eye?

From AQUA Scans:

Leticia's father, the current king, is very wise and knew that both of his older sons have their own supporters, and that if either one became king, the other brother's supporters would rebel—throwing the country into a civil war.

To prevent this, the king decided to announce that he will retire while he's still alive and make his daughter, the princess, his successor! However, the princess doesn't have any political allies. So she decides to gather a group of knights loyal to her and form her own "round table" before the day of her coronation.

The only problem is all of the good knights who are strong and skillful and loyal have already been snatched up by her father and brothers for their own personal guards...

(Based on a light novel, also being translated by AQUA Scans.)

A series of cleverly interconnected stories written from multiple POV's, tying together the quirky cast and a number of mysterious (and occasionally hilarious) occurrences in a certain suburb of Tokyo.