Nagai, Go

Soft-hearted Akira Fudou has always been somewhat of a pushover. When he reunites with his childhood friend, Ryou Asuka, in a fateful encounter, Ryou reveals to him the terrifying reality of his father's research: demons exist and are planning to claim possession of the earth once again.

Eager to help his friend save humanity, Akira agrees to attend Black Sabbath, a party filled with depravity and corruption, to attempt to merge with a demon. A near-death encounter causes him to unify with Amon, a demon feared amongst even his own kind. Together they form Devilman, a combination of Amon's strength and Akira's pure heart.

After uniting with Amon, Akira begins to fight against the demons with his newfound power, desperate to stop the downfall of all human civilization.

[Written by MAL Rewrite]

Devilman

デビルマン

Oku, Hiroya

Lonely high school student Kei Kurono isolates himself out of a growing cynicism toward his fellow man and the cruelty they are capable of enacting. One day, while waiting to take the subway to school, Kei's classmate Masaru Katou leaps onto the tracks in an effort to save a drunk man. Driven by an uncharacteristic desire to rescue someone else, Kei follows Katou down into danger. While successful in saving him, the two boys are killed by the train.

Kei wakes up beside Katou in an apartment full of strangers and furnished by a giant black orb with a glass-like outer surface. After finding out that everyone in the room has recently died, words appear on the black ball tasking them with killing a strange creature. The ball equips Kei and the others with power suits and mysterious guns before sending them off to collect this bizarre bounty.

Although Kei discovers the mission to be far more deadly than originally suspected, he manages to survive. He is teleported back to the apartment where he and the other survivors are rewarded point values according to their actions in battle by the black sphere, which a fellow survivor says is called "Gantz." Despite his death earlier that day, Kei is granted the ability to return to his daily life with one condition: he can be uprooted from his day at any time and summoned back to the apartment, where Gantz will task him and other recently deceased with the assassination of another target. 

While Katou dreads the inevitable return to Gantz, Kei finds himself living for the sole purpose of carrying out these missions. Thriving in the heat of battle and learning to care about himself and his comrades, Kei faces escalating monstrous threats that begin to bleed out into his normal life outside of Gantz.

[Written by MAL Rewrite]

Gantz

GANTZ

Mikage, Eiji

Tetsuo

Kazuki Hoshino values his everyday life above all else. He spends the days carefree with his friends at school, until the uneventful bliss suddenly comes to a halt with the transfer of the aloof beauty Aya Otonashi into his class and her cold, dramatic statement to him immediately upon arrival:

"I'm here to break you. This is the 13,118th time I've transferred. After so many occasions, I have to say that this is all starting to grate on me, which is why this time I'm spicing things up with a proper declaration of war."

And with those puzzling words, the ordinary days that Kazuki loved so dearly become a cycle of turmoil and fear—Aya's sudden appearance signals the unraveling of unseen mysteries surrounding Kazuki's seemingly normal friends, including the discovery of mysterious devices known as "boxes."

[Written by MAL Rewrite]

Utsuro no Hako to Zero no Maria

The Empty Box and Zeroth Maria

空ろの箱と零のマリア

Tamura, Yumi

Natsu Iwashimizu's last memory of her family is eating her favorite meals with them. Unfortunately, she wakes up from her dream only to find herself in a sinking ship, being rescued by three strangers: Arashi Aota, whose kind-hearted personality does not match his quick temper; Semimaru Asai, who enjoys ridiculing Natsu's meek nature; and Botan Saotome, a skillful woman seemingly aware of their situation. Following the four's successful escape, they sail to a deserted island.

Unbeknownst to them, the mysterious island is Japan. After a meteorite landed on Earth, humanity was wiped out and the environment changed drastically. To repopulate the country, the government initiated the "7 Seeds" project, consisting of five groups—Spring, Summer A, Summer B, Autumn, and Winter—each with seven young healthy individuals and a guide. Natsu and the others were put into team Summer B, whose members are considered failures by society.

To get more supplies, the group must find one of the seven shelters built by the government. In a hostile, unfamiliar world with no loved ones to depend on, the quartet must learn to cooperate with each other to ensure their survival.

[Written by MAL Rewrite]

7 Seeds

7SEEDS

Nihei, Tsutomu

In an enormous steel labyrinth riddled with horrifying creatures, humanity is forced to isolate itself in small enclaves while living in constant fear of its annihilation. In this dystopia, only a strange young man known as Killy is brave enough to traverse its unforgiving territories. 

Possessing superhuman strength and a rare Graviton Beam Emitter, Killy fights off bloodthirsty beasts and other fiendish forces in his desperate search for a human with the Net Terminal Gene—genetic information that holds the potential to restore the corrupt world. 

The dark world of Blame! follows Killy as he meets new people, sheds more blood, and draws closer to finding the Net Terminal Gene. Through these exploits, the true nature of the world is slowly pieced together.

[Written by MAL Rewrite]

Blame!

BLAME!

Song, Ji-Hyung

Takashige, Hiroshi

Haruka Touyama is a twelve-year-old girl with incredible precognitive abilites. But her accuracy in predicting the future has made her a target for any number of greedy corporations that would use her power for their own profits. After she is taken from her family, Haruka uses her gift to seek out someone who can help her escape her captors and fixes upon a blind man making his way through the busy streets of Tokyo. Though it may seem an odd choice, Haruka's powers have not led her wrong. Despite his inability to see, her chosen protector's fighting skills become apparent when he draws a sword from his walking stick and takes out a corporation's thugs. Haruka knows she will always be pursued and begs the mystery swordsman to keep her safe..."until death do us part."

(Source: Yen Press)

Shi ga Futari wo Wakatsu made

Until Death Do Us Part

死がふたりを分かつまで

Nanatsuki, Kyoichi

Night Owl

The world has become a desolate, lawless land where bandits roam free, innocent people suffer and demons lurk around every corner. Sona Yuki is traveling with his family when they are attacked by bandits, his entire family is murdered and he is left with a snake mark on his hand. As he is about to die, a woman comes up to him and gives him an option: continue to live in this harsh environment or die peacefully now. Yuki chooses life and Garami, the woman, gives him a second chance at life in exchange for his servitude. Garami is a weapons merchant and a gun for hire that travels from town to town for clients. Yuki sees how brutal and unforgiving this world can truly be.

(Source: MangaHelpers)

Kiba no Tabishounin: The Arms Peddler

牙の旅商人 ～The Arms Peddler～

Miura, Kentarou

Studio Gaga

Guts, a former mercenary now known as the Black Swordsman, is out for revenge. After a tumultuous childhood, he finally finds someone he respects and believes he can trust, only to have everything fall apart when this person takes away everything important to Guts for the purpose of fulfilling his own desires. Now marked for death, Guts becomes condemned to a fate in which he is relentlessly pursued by demonic beings.

Setting out on a dreadful quest riddled with misfortune, Guts, armed with a massive sword and monstrous strength, will let nothing stop him, not even death itself, until he is finally able to take the head of the one who stripped him—and his loved one—of their humanity.

[Written by MAL Rewrite]

Included one-shot:
Volume 14: Berserk: The Prototype

Berserk

ベルセルク

Iwaaki, Hitoshi

"Parasites" are tennis ball sized creatures, whose numbers and origins are unknown. They invade and take over the human mind in order to survive. Shinichi Izumi is a 16-year-old high school student who lives with his parents in a quiet neighborhood. One night, a Parasite invades Shinichi's body in an attempt to take control of it. However, it fails to complete the takeover process and ultimately ends up inhabiting only his right arm. 

Thus, both Shinichi and the Parasite—who calls himself Migi—retain their individual minds. Now in a peculiar "human and alien" relationship, Migi proposes that they cooperate to survive. Shinichi has no choice but to agree, and he must now cling to his morality as he and Migi face off against other bloodthirsty Parasites.

[Written by MAL Rewrite]

Kiseijuu

Parasyte

寄生獣

Endo, Hiroki

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.

Twenty years later, the boy is the most powerful drug lord in South America. He aids his son from behind the scenes as he evades and eventually with the help of mercenaries from Nomad (some of them former Propater operatives) fights the Propater. As the plot develops focus shifts away from the main character and develops many sub-plots dedicated to terrorism, Human-improvement, the struggle of the developing countries and the power battles between the drug cartels and Propater.

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

(Source: MU)

Eden: It's an Endless World!

EDEN ～It's an Endless World!～

Moriyama, Daisuke

America in the Roaring 20s. On the surface, it's a positive, peaceful time after the violence of the Great War. But lurking in the shadows is a dark element ready to snatch that peace away. Sister Rosette Christopher, an exorcist working as a part of the Magdala Order, has a duty to fight the demons which appear and cause destruction. But along with her companion Chrno, she usually ends up causing more destruction than the demons themselves! On one particular mission, they meet a young girl with a beautiful voice named Azmaria, who is being targeted by her own stepfather. As Rosette and Chrno work to save her, more is revealed about the relationship between them. There is more to these two than meets the eye.

(Source: ADV)

Chrno Crusade

クロノクルセイド

Sunao, Yoshida

Shibamoto, Thores

The background is in the distant future, a post-apocalyptic world after the destruction brought about by Armageddon. The war between humans (Terran) and vampires (Methuselah) continues, as a struggle between two factions: the Vatican and the New Human Empire.

Yet, amidst the bloodshed and violence, many desire a peaceful co-existence between the two species. However, standing between them and this goal is the Rosenkreuz Orden, a group of vampire extremists who manipulate the two sides and pit them against each other. To combat them, the Vatican special operations group "AX," led by Cardinal Caterina, must use everything they have—even a vampire who preys on the blood of other vampires.

(Source: Tokyopop)

12 Manga Like Devilman Lady