Luna Ishikawa is a unique transfer student who stands out as a vampire with a cool demeanor. Her classmates quickly notice her and are intrigued. Tatsuta Ootori, an ordinary student, assumes it's impossible to interact with someone like Luna. However, when the two are unexpectedly paired to clean together, their dynamic shifts. As they clean, Tatsuta develops an unexpected friendship with Luna, and his initial perspective of her begins to change. Luna isn't the poised and enigmatic girl he thought she was. In reality, she struggles with blood-sucking, a fundamental skill that all vampires should have. With a determination to help, Tatsuta offers to be her practice partner. Together, they add excitement to their dull school days by refining Luna's abilities through every bite she takes.