The MireMekagoji's name comes from the Millennium series, specifically the word mireniamu (ミレニアム?), meaning millennium, and Mekagoji, which comes from MechaGodzilla's Japanese name, Mekagojira (メカゴジラ?).
This MechaGodzilla redesign is radically different from previous versions, and bears a closer resemblance to Godzilla himself. The MireMekagoji is light silver in color, with various areas on its body explosing thick black wires underneath. The head has a long metal spike extending from the top of its forehead upward towards the back of its head. The eyes are large and relatively close together. They are usually yellow in color, but will turn red when Kiryu is possessed by the first Godzilla's spirit. A red scar extends underneath both eyes, and it will often glow when Kiryu roars. The suit's chest features three rounded plates that come together to cover the Absolute Zero Cannon housed underneath. When the suit is used to portray Super Weapons Kiryu, two blue rocket launchers are attached to its shoulders, while blue railguns are attached to its wrists.