In the 21st century, a family of vampires settled down on the
grounds of Japan and lived a modest life whilst sucking on the
blood of humans discreetly. However, the eldest daughter of the
family, Karin Maaka, has an embarassing secret which cannot be
revealed to anyone. Even though she is a vampire, she does not lack
blood like her family members. Instead, she overproduces blood to
the extent that she transfuses the excess into her victims, hence
increasing their blood levels. Despite her troubling body
characteristic, she attends school like any other high school
student, that is until a new transfer student, Kenta Usui, enters
her life.
