A mysterious alchemist studies and experiments to create "living creatures" called Chemies. Unfortunately, the cards holding them that should have been kept secret are accidentally unleashed on the world. High school student Houtarou Ichinose is tasked to retrieve all the Chemies released around the world. Using the Grasshopper Chemy, Hopper-1, and the Steam Locomotive Chemy, Steamliner, he transforms into Kamen Rider Gotchard!

Junsei Motojimaas Houtaro Ichinose / Kamen Rider Gotchard
Reiyo Matsumotoas Rinne Kudo / Kamen Rider Majade
Yasunari Fujibayashias Supana Kurogane / Valvarad / Kamen Rider Valvarad
Rikiya Tomizonoas Sabimaru Tsuruhara
Oto Abeas Renge Icho
Rikuto Kumakias Minato
Itono Okitaas Atropos
Kanon Miyaharaas Clotho
Alisa Sakamakias Lachesis
Saki Fukudaas Kyoka Edami
Keiichi Hasegawa
Hiroki Uchida
Akiko Inoue
Hiroshi Takaki