Aki Kodai is the wife of Kenryu Kodai and the mother of Ryuta Kodai. In the first season, she remains unaware that the dinosaurs are real, accepting her husband's cover story that they are merely unusual dogs. During a trip to Spain, she is confronted by the roar of an Allosaurus and faints, marking her first genuine encounter with a card dinosaur she did not believe to be an illusion. By the season's end, the truth of the dinosaurs, the D-Team's activities, and the Alpha Gang is exposed to the world. She forgives the team for their secrecy, including her husband's deception.

Her role expands in the second series, Mesozoic Meltdown, where she is abducted in the opening episode by the Spectral Space Pirates alongside the other parents. She remains their captive until the finale and briefly participates in a failed escape attempt before being recaptured by the Gel Jarks.