Hiyori, a high-school student with a complex about her small stature and elementary-schooler-like appearance, managed to get an injury thanks to her friends' teasing about her unrequited love. Unexpectedly, the infirmary is not only dark, but also has an underclassman, Kageyama, instead of the nurse. Even more unexpectedly, Kageyama suddenly confesses to being a vampire and having fallen for Hiyori at first sight, and then asks her to be his food. How is the modest Hiyori to deal with this stubborn and addlebrained kohai?