The mission of the Lotus Girls' Academy is to instill values of purity and modesty in young girls. Youko, a student at the academy, quickly forges a strong connection with Shuu. However, their bond takes an unexpected turn when Youko learns that Shuu is a vampire. Though hesitant, Shuu confides in Youko who promises to protect her secret. As they spend more time together, Shuu's emotions toward Youko become murky, and Youko discovers that her blood has an unusual taste to Shuu. How far will Youko go to support her friend, and what will this signify for their relationship?
