The Mountain Witch is a self-contained role-playing adventure in which players take on the role of ronin in mythical medieval Japan. Outcast and unemployed, these ronin accept a deal that no one else would take – to assault and kill the dreaded O-Yanma, the Mountain Witch of Mount Fuji.

These characters, haunted by their pasts and by dark fortune, have found themselves in a desperate situation. Though their reasons all differ, they all find themselves standing on the brink of losing everything. Only the payoff of this mission can restore their hope of a normal life and of regaining some of what they have lost. But can these men, with both everything to lose and everything to gain, be trusted? Can they overcome their differences and together move forward against the Witch? Or will they let dark fate overwhelm them?