Riko is the only child of the legendary cave raider and white whistle Lyza "The Annihilator." When Riko was two, her mother went missing during a quest to the bottom of the Abyss, after which Riko lived in the Belchero Orphanage, studying to become a cave raider herself.

By the age of twelve, Riko attained the rank of an apprentice, giving her the rights to wear a red whistle and explore the shallowest level of the Abyss. She dreams of attaining the white whistle rank (the highest among cave raiders) and following her mother to the bottom of the Abyss.

Riko is a good-natured and energetic child. She has a quick and inquisitive mind and tries to gather and properly organize all the information available on the subjects that interest her. Riko is resilient and stubborn and, while not much of a brawler, her ability to keep cool under pressure and make rational decisions in the heat of battle allows her—along with Regu's help—to successfully tackle many of the dangers the Abyss has to offer. She's also very good at cooking.

(Source: Wikipedia, edited)