The Cursed Lovers

At the age of 10, Zero Kiryu met Sakurako Sasaki. 4 years later they were the best of friends, and no one could split them apart. Until Sakurako was taken as hostage by a vampire, and was severely injured. Not long later the Vampire Hunter Association lied to her and told her that Zero was killed, they lied to protect her from the truth.
3 years have gone by since then, they are reunited again. This time the truth is said to her, but she is hiding something from Zero.