Eiko Anzai is an operator for the Mobile Rescue Police, first appearing as an ally in the third episode of the series. She is a support member who works primarily within the command center, providing critical assistance during emergency responses. Her background is rooted in her duties as an operator, a role she fulfills alongside her colleague Megumi Shinmon. In terms of appearance, she has olive or green hair tied in a ponytail, with chin-length strands framing her face, and distinctive grey eyes. Her standard uniform consists of a white shirt with a red tie, a dark blue skirt, and a blue jacket featuring a golden badge that reads DH.

Regarding her personality, Anzai is characterized as a dedicated member of the team who nonetheless seems somewhat inexperienced and uncertain of herself in the field. She maintains a strong commitment to her support duties but exhibits moments of hesitation and self-doubt, particularly when faced with direct danger. Her motivations stem from her role as an operator, focused on aiding the Mobile Rescue Police in their missions and ensuring the safety of civilians from the command center.

Her role in the story is primarily that of a command room operator, monitoring situations and coordinating responses. During a major crisis when the Evil AI takes over the Mobile Rescue Police headquarters, she takes direct action by helping Megumi Shinmon and Chief Arisa Munakata blast open a secured door, enabling the manual launch of the Drive Head units. Later, when the same Evil AI creates copies of the original generation Drive Heads to attack the headquarters, Commander Takahito Saionji assigns her to evacuate the civilian visitors who were touring the facility. During this chaotic attack, she is nearly hurt but is protected by Shun Kuroeda, the driver of the S.I.B. Max unit. Throughout the final confrontation against the supercomputer known as Ark, from which the Evil AI originated, Anzai remains in the command room watching the battle unfold. In the film continuity, she continues to work in the command room alongside Megumi Shinmon.

Key relationships include her partnership with fellow operator Megumi Shinmon, as the two work closely together in the command center. She also shares a connection with Shun Kuroeda, who protects her from harm during the attack on headquarters. Her development throughout the series shows a member who, despite her initial inexperience and uncertainty, proves capable of taking initiative in a crisis, such as when she helped blast open a door to launch the Drive Heads manually. Her willingness to carry out evacuation duties despite the personal danger demonstrates her dedication to her role. As for notable abilities, Anzai possesses operational and support skills essential for command center duties, including monitoring emergency responses and coordinating with field units. She also demonstrates the ability to take physical action when necessary, such as using explosive force to breach a door during the headquarters takeover.