Ashitaka, a prince of the disappearing Ainu tribe, is cursed by a demonized boar god and must journey to the west to find a cure. Along the way, he encounters San, a young human woman fighting to protect the forest, and Lady Eboshi, who is trying to destroy it. Ashitaka must find a way to bring balance to this conflict.
Mononoke is a spin-off of the Bakeneko story arc of Ayakashi - Japanese Classic Horror. It follows the Medicine Seller as he deals with various spirits or "Mononoke" in feudal Japan. Just like in the Bakeneko story, he combats with a series of tools and his vast knowledge of the supernatural on his side, but can only slay the Mononoke when he uncovers its form (Katachi), the truth behind its appearance (Makoto) and the reason for its unusual behavior (Kotowari). In other words : Truth, Form and Regret.
Ashiya has spent the first seven days of high school stuck in the infirmary because of a youkai attaching itself to him. He ends up asking the owner of a small tea room called the "Mononokean" for help. This is a tale involving the very morose owner of Mononokean guiding the youkai that happened to wander into this world go to the next world.