Dr. Tetsu Segawa (portrayed by Greg Paik) is a minor character who appears in the live-action Guyver film. He appears only during the pre-title scene, carrying with him a metal case containing the Guyver unit that he stole from his employers, the Chronos Corporation. A group of Chronos' Zoanoids - led by Lisker - chase the runaway doctor down to a junkyard to retrieve the unit. Segawa hides the unit amongst the waste and transforms into his Zoanoid form, but Lisker also transforms and the two mutants fight. Lisker proves to be stronger than Segawa and crushes the doctor's head in his hands.
- Tetsu Segawa is named after Tetsuro Segawa from the Japanese Guyver manga. Their characters are very different from one another, however. In the manga, Tetsuro was the brother of Mizuki Segawa, whereas Tetsu is the film Mizuki's father. In the film, Tetsu fulfills the role of Marmot from the manga and anime.