Demon Lord Dante vs. Getter Robo G is a sequel to Devilman vs. Getter Robo with the Getter Team reappearing to fight the threat that comes from a cult worshiping the ancient demon lord Dante.
Some time after the battle with the demons and Dinosaur Empire alliance, the Getter Team now including Benkei Kuruma in the New Saotome Laboratory are deployed to investigate some strange occurrences. A cult worshiping the demon lord Dante attempts to awaken the ancient demon through a sacrifice and using Ryo Utsugi as the catalyst to bring Dante into being. However the Getter Team intervenes with the ritual causing Ryoma to fused with Dante instead. Ryo was rescued by Dante's former lover Medusa and encountering the Getter Team agrees to work with them to rescue Ryoma.