Naoto Tamura

Naoto Tamura/Mobile Cop Jiban is a human revived as a cyborg by Doctor Igarashi to fight Bioron. He is capable of reverting to his human identity at will. He holds the rank of police commissioner (as a robot) and detective (as human). Jiban's programming enables him to follow these directives: 1. Arrest criminals in any circumstance without a warrant. 2. Punish criminals on his own judgment if they happen to be members of Bioron. 3. Use lethal force depending on the circumstances.

In human form, Naoto often plays the fool and is looked on down by Youko and Kiyoshirou for this, but Youko begins to warm up to him after realizing he could be Jiban.