Call of the Night Vol. 2 (manga)

What's the difference between desire and love? Does Nazuna know any better than Ko? What about Ko's childhood friend Akira? Unable to answer these romantic questions, Ko and Nazuna go swimming. Turns out bathing beauties at pools are just as hot at night as in the blazing sunshine at the beach. Then, Ko gets jealous when he learns about Nazuna's night job... But when she drafts him into temping for her, the two of them join forces to save a client from her boss--and herself.