Gatsu was brought up by a mercenary group since birth. After killing his guardian in self-defence, he runs away. Years later, he encounters Griffith and The Band of the Hawk. The Hawks fight for the King of Midland, and after winning the 100-year war against the neighbouring Chuda, they become the King's personal guard. However, once they reach the top, things take a turn for the worst.

Light Yagami is an extremely intelligent young man who resents the crime and corruption in the world. His life undergoes a drastic change when he discovers a mysterious notebook, known as the "Death Note", lying on the ground. The Death Note's instructions claim that if a human's name is written within it, that person shall die. Light is initially skeptical of the notebook's authenticity, but after experimenting with it, Light realizes that the Death Note is real. After meeting with the previous owner of the Death Note, a shinigami named Ryuk, Light seeks to become "the God of the New World" by passing his keen judgment on those he deems to be evil or who get in his way. A shinigami's Death Note is a notebook that can kill any human whose name is written in it. All Death Notes are governed by the same set of rules determining the extents and limitations of the Notes' powers.

The Diclonius, a mutated homo sapien that is said to be selected by God and will eventually become the destruction of mankind, possesses two horns in their heads, and has a "sixth sense" which gives it telekinetic abilities. Due to this dangerous power, they have been captured and isolated in laboratories by the government. Lucy, a young and psychotic Diclonius, manages to break free of her confines and brutally murder most of the guards in the laboratory, only to get shot in the head as she makes her escape. She survives and manages to drift along to a beach, where two teenagers named Kouta and Yuka discovers her. Having lost her memories, she was named after the only thing that she can now say, "Nyuu," and the two allow her to stay at Kouta's home. However, it appears that the evil "Lucy" is not dead just yet...

Hellsing is Holy Order of Protestant Knights, led by the latest member of the legendary Hellsing bloodline, Sir Integra Fairbrooks Wingates Hellsing. Their mission is to protect Queen and Country from the forces of the Undead and the forces of darkness. She is served by her faithful family butler and former Undead hunter, Walter C. Dornez. Amongst them is Alucard, a powerful vampire that was captured by the family hundreds of years ago, and his newly turned servant, Seras Victoria. It is after this attack that the main villians of the story are introduced: Millennium, a splinter organization of the Nazi army led by Major Montana Max.

Ten years ago, young Integra Hellsing ascends to the head of the Hellsing Organization after the death of her father Arthur. Her jealous uncle Richard Hellsing attempts to kill her, but in doing so awakens a dormant Alucard, who proceeds to kill Richard's men. It is Integra who shoots and kills her uncle, thereby becoming the last descendant of the Hellsing bloodline. Alucard declares his allegiance to Integra and becomes her loyal servant. In present day England, Alucard is called to duty to eradicate a vampire priest and his ghouls. However, a police girl named Seras Victoria is gravely injured in the process, and upon giving her a choice to live or die, Alucard turns her into his vampire servant. Later, on a mission to hunt down a vampire in the town of Badrick in Northern Ireland, Alucard meets and fights Father Alexander Anderson for the first time.

The background is in the distant future after the destruction brought about by Armageddon. The war between the vampires and the humans continue to persist. In order to protect the humans from the vampires, Vatican has to rely on other allies to counter the situation. The protagonist, a priest called Peter Abel Nightroad, travels through the countries as a representative for the Vaticans. However, he is also part of "Ax", a special operations group controlled by the Cardinal Catherina. His encounter with a young girl called Esther will determine the struggle and survival between the human race and the vampires.

Yuki Cross's earliest memory is of a snowy night in winter, when she was attacked by one vampire and was saved by another, Kaname Kuran.Yuki is the adopted daughter of the Headmaster of Cross Academy, Cross Kaien and has grown up and became a prefect for the school with one main purpose: to protect the Human Day Class Students and the Vampire Night Class Students from each other. Her fellow guardian, Zero Kiryu, a childhood companion whose parents were killed by a pureblood vampire, is now determined to kill them all and refuses to trust them. Through a cruel twist of fate, Zero becomes a vampire himself, having been bitten by a pure-blood vampire four years before, Shizuka Hio. Kaname leads the group of Night class as their President, with the help of Takuma Ichijo, the Vice-president.

Yuuki wants to know more about her true family and her forgotten past and starts a research. The secret will be revealed. Yuki, Kaname and Zero will show the begining of a new mystery and a forbidden love.

Robin Sena is a "craft user", born in Japan and raised by the Roman Catholic Church in Italy. She is trained to use her craft (fire) to hunt down witches. Witchcraft is a genetic trait, dormant within a number of individuals within the human population. Powers can be "awakened" in these dormant human "seeds" at any time. Trained hunters, craft-users or "seeds" themselves, are needed to keep watch over "seeds" and hunt those whose abilities become active, serving in secret organizations, such as the parent branch "Solomon" (and the "STN-J" branch in Japan), as self-appointed witch police to curtail the use of witchcraft in society, and to keep the witch kind in secret from the public. Even the police, who cooperate with STN-J in abnormal criminal cases, do not know what STN-J does.