Riku is one of the main characters in the Kingdom Hearts series. Riku lives on Destiny Islands. He is the best friend of Sora and Kairi. Riku is five years old during Kingdom Hearts Birth by Sleep, fifteen during the events of Kingdom Hearts and Kingdom Hearts: Chain of Memories, and sixteen during the events of Kingdom Hearts 358/2 Days and Kingdom Hearts II. Riku's name is derived from the Japanese word for "Land", etc.