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...

Ko's powers increase formidably and dangerously. Nazuna learns a new vampire rule about love that could be her undoing. To make matters worse, an enemy discovers the object capable of destroying her! Meanwhile, while Azami and Susuki continue to pursue heartless vampire Kiku, Kiku meets...Mahiru's mom?