For their "school trip", Mahiru and Kiku chose to go to Hokkaidô. Barely arrived there, Kô, launched in their footsteps, met a vampire in school uniform. It seems that this boy is not a stranger to Nazuna! "Aaaaabruututiiii!" The appearance of this young man explodes the anger of Ko and gives a new direction to his journey in pursuit of Mahiru and Kiku!