Kuro is a super unmotivated vampire, always griping about even the most menial of tasks. When he's paired with high school student Shirota Mahiru, the two end up joining forces with the C3 combat trio. But what is C3 hiding about Tsubaki's motives? And what's up with Tsurugi's personality change? Follow Mahiru as he tries his best to work alongside a trio of childish adults in this comedy full of vampires and heart-racing battles!