Auru serves as a member of the unit Mechanica Metallica within the Technoroid universe. He displays a lethargic and unfriendly personality, marked by low motivation and a generally negative outlook. Frequently expressing a desire to return home to charge, he typically avoids social interactions and redirects inquiries about his experiences to fellow members like Silve. Despite this unmotivated demeanor, his unique surroundings and unit members frequently compel him to participate in activities.

As Mechanica Metallica's primary composer, Auru creates songs and devises strategies for climbing the entertainment tower Babel. This role as the unit's strategist and songwriter underscores his intellectual contributions, contrasting with his otherwise withdrawn nature. He possesses the special ability "Pulse Analysis," enabling him to monitor human pulse rates and perform basic health assessments.

Technically, Auru shares a close origin with Silve: both were manufactured on the same date, at the same location, and using the same type of machine. His serial number, AU-0813WG, incorporates "AU" as a reference to gold (Aurum) from the periodic table. He is also known by the player name "A" in an unspecified shooting game, as mentioned in a Unison Story.