In the distant future, in a tropical city on the ocean, fifteen-year-old Mizuki Maia is expecting to be accepted into the prestigious Ocean Agency after acing her entry exams.

Even getting caught up in a shootout, as a bystander, between two bikini-clad young women on scooters (part of the Nereids Kamchatka branch as it turns out) and some gunmen, does not phase Maya much. But when she returns home things start to go very wrong...