Eiko Anzai operates within the Mobile Rescue Police command center, providing critical support during emergency responses. She possesses olive hair styled in a ponytail, with shorter strands framing her face, and distinctive grey eyes. Her attire consists of the standard uniform: a white shirt topped by a blue jacket featuring a golden "DH" badge, accented with a red tie, and paired with a dark blue skirt.

Characterized as dedicated yet somewhat inexperienced, Eiko exhibits moments of uncertainty in her duties. She works closely alongside fellow operator Megumi Shinmon. During the Evil AI's hostile takeover of headquarters, Eiko demonstrated quick action by blasting open a secured door, enabling Chief Arisa Munakata and Shinmon to manually launch the Drive Heads. Later, when replicated Drive Heads attacked, Commander Takahito Saionji assigned her to evacuate civilian visitors; she was nearly caught in the crossfire but was shielded by Shun Kuroeda, pilot of the S.I.B. Max unit. Throughout the final battle against the supercomputer Ark, Eiko remained at her command center post, monitoring the conflict.

She also fulfills her operator role alongside Shinmon during the android Terra's assault in the film continuity. The characters in her given name, Eiko, signify "reflection" (映) and "child" (子), while her surname, Anzai, combines "peace" (安) and "equal" (斉).