Eiko Anzai serves as a dedicated support operator within the Mobile Rescue Police command center. She has olive hair pulled into a ponytail, with chin-length strands framing her face, and grey eyes. Her standard uniform is a white shirt with a red tie, a dark blue skirt, and a blue jacket bearing a golden "DH" badge.

Despite occasional self-uncertainty and inexperience, Eiko demonstrates commitment to her duties. During the Evil AI's takeover of headquarters, she actively assisted Megumi Shinmon and Arisa Munakata by blasting open a door to enable the manual launch of the Drive Heads. When the same AI later attacked with copied Drive Heads, Commander Takahito Saionji assigned Eiko to evacuate civilian tour groups, a task that placed her in direct danger during the assault and required protection from Shun Kuroeda, driver of the S.I.B. Max unit. She consistently monitors major conflicts from the command room, including the final battle against the supercomputer Ark. In the film continuity, she maintains this command center role alongside Megumi Shinmon.

Her surname Anzai combines the characters for "peace" (安) and "equal" (斉), while her given name Eiko uses "reflection" (映) and "child" (子).