The antisocial, awkward Ko is searching for a fun and sexy vampire to provide him with blood and turn him into her servant. One sleepless night, Ko hits the streets. Life after dark is a revelation! Especially when he meets the flirty Nazuna. However, she is a vampire. That's okay. He also wants to become a creature of the night. But the transformation is not that easy... What is the difference between desire and love? Does Nazuna know better than Ko? What about his childhood friend, Akira? Unable to answer these romantic questions, Ko and Nazuna go swimming. It turns out that beautiful girls in pools are just as sexy at night as they are in the hot sun at the beach. Then, Ko gets jealous when he learns about Nazuna's night job... But when she recruits him for support, the two team up to save a customer from her boss and herself.