Animal Doctor (2003)

Into every generation a slayer is born: one girl in all the world, a chosen one. She alone will wield the strength and skill to fight the vampires, demons, and the forces of darkness; to stop the spread of their evil and the swell of their number. She is the Slayer.

In his past life, he was known as Demon Lord Varvatos, an all-powerful magic user and ruler. But he was lonely after the loss of his friends and loved ones during his rise to power, so in his dying moments, Varvatos cast a reincarnation spell so that he'd get a second chance at just being a normal guy. At first it looks like that's going to work – he's reborn thousands of years later as villager Ard. Unfortunately for him, his memories are still intact and he's not aware just how much has been lost over the time he spent not existing, and it looks like that's going to cost him his normal life.

Toujou Basara is a high school student whose father has suddenly just remarried. His father then departs overseas leaving Basara with two new beautiful step-sisters. Little does he know, his new sisters, Mio and Maria are actually the new Demon Lord and a succubus!? Almost trapped into a life of servitude, Basara forms a reverse contract by accident and ends up becoming Mio's master! Hijinks ensue as Basara finds himself in one ecchi situation after another. However, Mio's life is in danger as she is pursued by demons and heroes!

One hundred years ago, a grave tradition was born in a land where demons live among people: a human must be sacrificed to the King of Beasts. But when Sariphi, the 99th sacrifice, is offered to the King, she isn’t afraid at all! Intrigued by her calm and cute nature, the King decides to spare her life with plans to make her his bride.

Natsume Takashi has the ability to see spirits, which he has long kept secret. However, once he inherits a strange book that belonged to his deceased grandmother, Reiko, he discovers the reason why spirits surround him.

During the Warring States era, the feuding generals were suddenly struck down one after another by the demonic Kishin. In the 150 years since, groups of individuals have continued to resist Kishin control. They are called Bushi bands. When they were young, Musashi and Kojiro would hear tales about the Bushi from Kojiro's father, and the two of them dream to form the strongest Bushi band. One day, as Musashi struggles with his choices, he witnesses humans being torn apart by oni. Forced to face the truth, Musashi rises up against the powerful oni to make his dream with Kojiro come true!

Staz is a vampire from the surreal "Demon World", and Fuyumi, an ordinary girl, accidentally wanders into the Demon World through a portal. Subsequently after meeting each other, Fuyumi is killed by a carnivorous plant and turned into a ghost, causing Staz to take responsibility and pledge to help bring her back to life.

Nanami was just a normal high school girl down on her luck until a stranger’s lips marked her as the new Land God and turned her world upside down. Now, she’s figuring out the duties of a deity with the help of Tomoe, a reformed fox demon who reluctantly becomes her familiar in a contract sealed with a kiss. The new responsibilities—and boys—are a lot to handle, like the crow demon masquerading as a gorgeous pop idol and the adorable snake spirit who’s chosen the newly minted god to be his bride. As the headstrong Tomoe tries to whip her into shape, Nanami finds that love just might have cute, pointed fox ears. With romance in the air, will the human deity be able to prove herself worthy of her new title?

Unable to remember the past, high school senior Saya Otonashi must rediscover her destiny in order to defeat the chiropteran vampires that threaten her loved ones' existence.

Three months have passed since the Demon Lord was struck down, and the Demon Realm is holding a tournament to select his replacement. The leading contestant is Helck, a human hero who claims to hate his own kind. Some aren't happy with the idea of a human becoming the next Demon Lord—especially Vermilio the Red. She wants nothing more than to protect demonkind and prove Helck to be their enemy, even if she has to rig the competition to do it!