Okko Chronicles sees players take on the role of the legendary Ronin and his traveling companions as they move through the Palace of Mists to uncover a dark conspiracy and defeat the demonic oni that lies at its heart.
During a game, one of the players will take on the role of the Oni, assisted by an army of supernatural creatures and mortal thralls, they will try to achieve their objectives and flee the palace before being unmasked by the heroes.
The remaining players will take on the role of one of the Pajan Empire's most notorious band of demon hunters. These heroes must quickly discover the Oni's nature and identify which of the palace's courtiers the evil demon has been using as a disguise.
The game ends when the Oni has completed its devious scheme and escaped or it is defeated in a deadly, climactic showdown with the heroes.
The heroes' actions have great influence over the course of Pajan's history. While failing to defeat the Oni may see the heroes remember as little more than notorious scoundrels, their honor and reputation may be redeemed if they can successfully thwart its plans.