Movie War Mega Max featured the first seven Kamen Riders (Kamen Rider 1, 2, V3, Riderman, X, Amazon, and Stronger) to commemorate the franchise's 40th anniversary. Trailers for the film shown during airings of Fourze also showed the return of Kamen Rider Double as well as a new form for Kamen Rider OOO. Unlike previous Movie War films, where they were divided into 3 segments, Movie War Mega Max is divided into 5 parts. Like previous Movie War films the secondary Kamen Rider of Kamen Rider Fourze, Kamen Rider Meteor, made his debut in the film.
Shu Watanabe
Ryosuke Miura
Sota Fukushi
Erina Mano
Renn Kiriyama
Tetsu Inada
Takahiro Fujimoto
Hirofumi Tanaka
Takayuki Masuda
Isshin Chiba
Koji Tobe
Hideo Ishikawa
Riho Takada
Marie Kai
Mayuko Arisue
Hiroaki Iwanaga
Asaya Kimijima
Jouji Nakata
Akira Kushida
Kenji Hamada
Atsushi Arai
Takashi Ukaji
Masaki Suda
Fumihiko Tachiki
Dante Carver
Sanae Hitomi
Azusa Watanabe
Toru Masuoka
Ryuki Takahashi
Yoshiko Sengen
Justin Tomimori
Rikako Sakata
Shiho
Shion Tsuchiya
Takushi Tanaka
Shingo Tsurumi
Rie Tanaka
Ryo Yoshizawa