Princess Sofia is the crown princess of Skyriver, who sometimes assists the Guardian Angels in their tasks.
Sofia is the crown princess of Skyriver. When the country of rainbows was invaded by the , Sofia stepped up and used her powers and knowledge to fight them as well. However, even with the help of the princess, Skyriver fell. Even after her kingdom had been destroyed and the troops of Skyriver were defeated, Sofia still had faith in the powers of the holy light and sent the Keepers of Rainbows to earth to find those who were born with the chromosome of light. At the moment, Sofia does her best to build a "new Skyriver", that may bloom even brighter than the former Skyriver.
Sofia met the Guardian Angels Of The Sky for the first time in Towards the Sky! Spring Vacations at the Rainbow Country's Wonder Forest!, when she invited them to thank them for their great work in fighting the eternal darkness. Later on, she granted the angels a great power that allows them to perform stronger attacks.