The demo opens with our pair of protagonists, Misha and Kirika, returning to the demon castle where they work. When they arrive, they discover that their castle is on fire! A dying fellow servant of the demon lord Maxim informs the twin demon maids that the castle has been raided by a competing army of devils. The heroines will have to work together to clear the castle and save their beloved lord!

Servants of the Dark stars a pair of new protagonists: Kirika and Masha. The two maids work for a deposed Demon Lord named Maxim. They must work together to secure revenge for Maxim and restore him to power in the Demon Realm. Like the first game, both "Gal Guardians" will play completely differently from each other.