Hikari to Mizu no Daphne

In a future where most of the Earth is submerged due to global warming, a 15-year-old orphan named Maia Mizuki, who recently graduated from middle school, applies to the prestigious Ocean Agency, a paramilitary organization under the world government. Only top students in intelligence and physical fitness are accepted. Maia, the main character, is expected to be among them, but she unexpectedly fails her entrance exams. Soon after, she is evicted, robbed, kidnapped, and shot. She is rescued by two women, Rena and Shizuka, who work for a freelance group called Nereids. With no other options, Maia joins them, taking on various jobs, from capturing fugitives to retrieving lost pets. Later, Gloria and Yu also become part of the team. A subplot involving "Daphne" emerges midway and becomes significant to Maia. The title "Brilliant Blue" reflects the water-dominated world, consisting of oceans, scattered islands, and floating cities.