In 2 years since Rain’s 3rd album, Rain released his 4th album 'Rain's World' at the World Tour Premiere on Oct. 13, 2006. The concept of 'Rain's World' is 'the angel who won against evil'. The cover's visual is the result from Rain’s numerous modifications.

Rain expresses the meaning of 'Natural rains to wash away the dirt and filth'. As a singer, ‘Rain wishes he could contribute to purify the darkness in this world’. The star on his chest is a symbol of 'war, peace, pain, hope, and love'. Through these conflicting words, he expresses the corrupted world and suggests the curing method.