Description by LuffyNoTomo Translations:

A long time ago there were vampires who had an allergy to RH+ blood, therefore they decided to only drink RH- blood. However, humans who carry this type of blood are rare. The vampires with this allergy created a safeguard academy for humans who carry this blood type. Within this academy they are promoting love relationships among the humans as cultivation.

Saika is one of the girls who carries RH-, ever since she was little she looked more like a boy and was teased so she decided to become stronger and less girly. Aoi is a good looking guy and her childhood friend. A handsome top breed vampire who is head of the student council named Ichika made an announcement that the guys and girls will start living together.

Aoi asked Saika to live with him and she ended up agreeing, however Ichika whom is her stalker wanted to live with her. Ever since that day when he followed her and she fell down, some blood hit the ground and Ichika tasted it. Since then he's been infatuated with her blood and thinks she's the one for him! However, Aoi wont back down from her either, why is that!?