Hideo Sawaki (澤木 英夫, Sawaki Hideo) is a character in Ronde.
A twenty-four year old lecturer at T University, he is a non-combat character who helps Asuka Miroku and the others in investigating the demon appearances by offering advice. The first stage he appears on is the Yoyogi Park stage that follows the Tokyo National Museum fight.
He holds a theoretical physics doctorate, but has an interest in archeology and works as Professor Ando's assistant. Hideo is also childhood friends with Sysop.
- The name Hideo means "excellent, fine" (英) (hide) and "man, husband" (夫) (o).
- Hideo's surname Sawaki means "marsh" (澤) (sawa) and "tree, wood" (木) (ki).