The tank-like "Gear Metal LEX" is a reference to the titular robots from the Metal Gear series. Although the two vehicles don't resemble each other, the name is most similar to the "Metal Gear REX" first seen in Metal Gear Solid.

Asagi was originally supposed to get the role of the main character in the planned sequel, Makai Wars. However, the game was indefinitely postponed, which has led to Asagi being a recurring character in many Nippon Ichi games, usually trying to steal the spot of the main character for herself.