Riko was raised by his uncle Tetsuji Moriyama in Castle Evermore. Once Kevin's mother died, they were raised together. Because Tetsuji was busy, they spent their time with the team and were considered their unofficial mascots. Their life consisted of playing Exy - they even had personal tutors so they didn't have to leave the stadium for school.
Kevin and Riko were inseparable and both grew up in front of the cameras. This led to an obsession with the two of them and many considered them the future of Exy.
Riko has the number 1 tattooed on his left cheekbone. Kevin has the corresponding number 2. When they were children, they used to draw the numbers on with permanent marker and retraced them when they faded. Riko is 5'5".