I don't not own Kingdom Hearts. It belongs to Disney and Square Enix but if I did. The third game of the main series would have been out years ago. —Riku, to Sora and Kairi In Kingdom Hearts, Riku is a calm, cool, collected teenager who is not afraid to push the boundaries. This is illustrated by his lack of. Riku is five years old during Kingdom Hearts Birth by Sleep, fifteen during the events of Kingdom Hearts and Kingdom Hearts Chain of Memories, sixteen during the events of Kingdom Hearts /2 Days and Kingdom Hearts II, and seventeen during the events of Kingdom Hearts 3D: Dream Drop Distance.