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...

A visit to the night school Nazuna attended years ago yields new insights into her forgotten past. Niko, her former vampire instructor, reminds Nazuna about her first friend, Kyoko. To aid in the investigation, Ko must pretend to return the affections of a boy-crazy student. Then, as more clues are discovered, a tale of friendship, betrayal, and murder unfolds...