Antisocial and curious, Ko is looking for a fun and sexy vampire to turn him into her submissive. One sleepless night, he decides to walk the streets. Life after dark is a revelation, especially when he meets the playful Nazuna. But she is a vampire. That's okay, as he wants to become a creature of the night too. However, the transformation is not as easy as he imagines...

Ko seriously weighs the pros and cons of becoming a vampire. However, every person has a different opinion on this, and one simply wants to kill them all! When the police are alerted to Ko's nighttime outings, they start causing him trouble. Ko discovers something amazing about the vampire Haka and receives a tempting offer. Nazuna changes her mind, but not about everything. And Ko wants to find out what the vampire Kiku's intentions are regarding his human friend, Mahiru...