Uchuu Tantei Divan is a follow-up to Jantei Monogatari, though it can be hardly considered a true sequel because of its entirely new setting and themes. Set in a sci-fi environment, the game casts the player in the role of Divan, a young man who possesses the ability to transform into a powerful supernatural being, and is entrusted by military authorities to protect Earth against an alien demonic attack.