In Godzilla vs. Mechagodzilla 2, Aso is introduced as stern and ruthless, reluctant to admit defeat and not above showing his temper. He proceeds with a plan to use Baby Godzilla as bait despite a general air of disgust amongst his colleagues and orders Miki Saegusa to locate and eliminate Godzilla's secondary brain despite her moral conflict.
By the events of Godzilla vs. SpaceGodzilla, Commander Aso’s character has softened, revealing a measured and philosophical side. He responds diplomatically when M.O.G.U.E.R.A. is reassigned to attack SpaceGodzilla instead of Godzilla. He is also forgiving of soldier Akira Yuki's erratic behavior, and it is revealed that he was once Yuki's superior officer. When M.O.G.U.E.R.A. is finally destroyed, Commander Aso’s immediate concern is for the fate of its pilot, Akira Yuki.
In Godzilla vs. Destoroyah, Aso struggles with orders not to attack Godzilla, as doing so could cause an explosion. Impressed by Little Godzilla's transformation into an adult Godzilla, it is Commander Aso who names him Godzilla Junior. Throughout the battle between Godzilla and Destoroyah in Tokyo, he is concerned for the safety of missing psychics Miki Saegusa and Meru Ozawa. Following Godzilla's death, Commander Aso expresses no joy; along with his colleagues, he is quietly aggrieved.
- The role of Commander Aso was the first role in a Godzilla film for actor Akira Nakao, who would go on to play more roles in the Millennium series.