Dawn of the Deep Soul continues the epic adventures of young explorers Riko and Reg, who are joined by their new friend Nanachi as they descend into the Abyss' treacherous fifth layer, the Sea of Corpses. There they encounter the mysterious Bondrewd, a legendary White Whistle whose shadow looms over Nanachi's troubled past. Although Bondrewd is ingratiatingly hospitable and the trio soon becomes fast friends with his gregarious daughter, Prushka, the brave adventurers know things are not always as they seem in the enigmatic Abyss...