I want to be a vampire's lunch.

"My name is Yuki Kito. I'm a vampire. Nice to meet you." When I entered high school, there was a vampire girl in the same class. How do vampires eat lunch? "Um... I haven't eaten. Blood packs for drinking are in short supply..." What?! Are you okay?! She can't eat a normal bento, her only source of nutrition isn't available, and she always spends lunchtime alone... I can't just leave her like that!! "Kito-san──my blood, do you want to drink it...?" Behind the deserted school building, our secret lunchtime began.