Toshihiko Sahashi
The first opening theme is the Queen-inspired "BIG-O!" Composed, arranged and performed by Rui Nagai. The second opening theme is "Respect," composed by Toshihiko Sahashi. The track is an homage to the music of Gerry Anderson's "UFO", composed by Barry Gray. In 2007, Rui Nagai composed "Big-O! Show Must Go On," a 1960s hard rock piece, for Animax's reruns of the show. This opening was subsequently used in the 2007 North American DVD re-release of the series. The closing theme is "And Forever," written by Chie and composed by Ken Shima. The duet is performed by Robbie Danzie and Naoki Takao. When the series was re-broadcast on the Animax channel, a new theme song composed and performed by Nagai titled "Big-O! Show Must Go On" was used for the opening sequence, instead.