Things that I only just found out today:
- The theme song was released as a single and the B-side is a version of the song sung by Hiroshi Fujioka himself (Segata Sanshiro)! I happened to be listening to him singing the other day on the Kamen Rider CD I bought. You can download the Segata Sanshiro theme from this page! The Hiroshi Fujioka version is a bit creepy...
- The music for the theme song is written by Ichirou Tomita and he sings it too. His alias as an anison singer is MoJo. He's sung the songs for tokusatsu sentai shows like Battle Fever J, Goggle V, Dynaman, right up to insert songs for Gaoranger and Boukenger. And the OP for the robot anime Albegas, too...