However, just a novice Red Whistle herself, she is only permitted to roam its most upper layer.
Riko, daughter of the missing White Whistle Lyza the Annihilator, aspires to become like her mother and explore the furthest reaches of the Abyss. The best and bravest of the Divers, the White Whistles, are hailed as legends by those who remain on the surface. How did it come to be? What lies at the bottom? Countless brave individuals, known as Divers, have sought to solve these mysteries of the Abyss, fearlessly descending into its darkest realms. The Abyss-a gaping chasm stretching down into the depths of the earth, filled with mysterious creatures and relics from a time long past.