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...

Our human friends are attacked by a mysterious male vampire. Luckily--or unluckily, depending on your point of view--Ko's half-vampire mode is growing ever more powerful. Who turned the attacker, and what is he after? No sooner are these questions answered than new ones arise as a second attacker arrives on the scene--and she's targeting both humans and vampires!