The idea of creating Raiden originated from Hideo Kojima's desire to view the series' protagonist Solid Snake from a different point of view, inspired by the Sherlock Holmes stories. Raiden's inclusion in the game remained a secret to gamers before the release of Metal Gear Solid 2; despite some players' reactions, the staff liked his character. He was voiced by Kenyu Horiuchi in the Japanese versions of the games and by Quinton Flynn in the English adaptations.