Ayumu was murdered by a serial killer – at least, he was. For after the mysterious Eucliwood Hellscythe revives him, he changes from a human to a zombie, much to his dismay. Now, in addition to being unable to die, the boy must see to the whims of his supernatural, silent companion – but things continue to get worse from there. As once Ayumu accidentally steals a magical girl named Haruna's powers, he is tasked with the embarrassing, obnoxious task of being a magical girl – err, boy – in her stead! Then with the addition of a hostile vampire ninja to his household, can Ayumu manage to maintain his new home life, fight against attacking monsters, and track down the person who killed him all while attempting to keep what little dignity he has left in tact?
Itsuka Tenma no Kuro Usagi and Kore wa Zombie desu ka have a whole lot in common. They both have dark fantasy settings where the male protagonists are made more or less unkillable by the main female characters, who are both extremely powerful magical beings who live cursed lives.
They differ in the style of execution. Itsuka Tenma no Kuro Usagi tends towards semi-serious angst-driven drama, while Kore wa Zombie desu ka favors completely over-the-top wacky comedy.
Both series have this immortal guy who keeps going on about the girl who made him immortal that he has to protect. Both series contain the same style of fighting and harem elements(lots of girls, only one-two guy(s)).
Kore wa focusses on the humor that you can have with a guy who just can't die, while usagi has more serious fights and actually tries to tie a story to the whole. If you're looking for magical combat, check them both out. If you're only in it for the humor/story elements, best stay clear of the other side of this rec.
Both of these anime involve vampires (though Fortune Arterial is more vampire-focused, whereas Itsuka Tenma no Kuro Usagi has other fantasy elements as well). They both spend quite a bit of time on things not directly related to the main conflict - such as romance and school life. Both have school as a central setting. And, of course, both seem comfortable with bits of fanservice here and there. Though that last bit could be a turn off if you're anything like me.
The art is similar - fairly bright and bishoujo. Unlike most other vampire anime, these two steer away from a very dark atmosphere.
Granted, I only made it halfway through Itsuka Tenma no Kuro Usagi, but I'm fairly confident thant fans of one anime will like the other.
Following a violent incident in his childhood, Alma Tandoji has been left an outcast at school and wants nothing more than to be quietly left alone. But one day Alma's solitary peace is shattered when a strange monster known as a Dark Stone attacks his hometown. Suddenly the boy finds himself thrust into the struggle between this strange creature and the ones fighting it: the Aiba Foundation and it's leader, the wealthy Ruri. Though reluctant to fight at first, amidst the battle, Alma learns that he possesses a power known as Sacred Seven that is linked to not only these mysterious creatures but also his forgotten past. Now, along with the help of Ruri and her bestpectacled butler Makoto, Alma must take up the mantle of protector to save the world from this new threat.