A mysterious alchemist studies and experiments to create a "living creature" called a Chemy. Unfortunately, the cards that should have been well-kept accidentally slipped together. A high school student named Houtarou Ichinose accidentally got involved and was given a task to return all the Chemies that were released around the world. He transformed with the Grasshopper Chemy, Hopper 1, and the Steam Locomotive Chemy, Steamliner to become Kamen Rider Gotchard.