One sleepless night, Ko slips out to walk the streets. Life after dark is a revelation! Especially when he meets flirtatious Nazuna. Except that she's a vampire. That's okay. He wants to become a creature of the night too. But transformation doesn't come that easily...

To sign up for his class trip to Hokkaido, Ko has to, well, go to school! His estranged friend Mahiru decides to travel to the island independently along with an unwelcome companion (unwelcome to Ko and company, that is). And things only get worse when Ko's fanged female followers join him and Akira on the train ride there!