Kamen Rider × Kamen Rider OOO & W Featuring Skull: Movie War Core is a 2010 film in the Kamen Rider Series, featuring the casts and characters of Kamen Rider W and Kamen Rider OOO. Originally announced in a teaser at the end of the film Kamen Rider W Forever: A to Z/The Gaia Memories of Fate, film was released in Japan on December 18, 2010. The catchphrase for the movie is "Kamen Riders, to the inner core of the Earth." Actor Taro Yamamoto guest stars in the film as the former partner of Sokichi Narumi, Koji Kikkawa reprising his role as the character. Both Kikkawa and Maki Ohguro are tied to a theme song (and music video) for the film, recording the song "HEART∞BREAKER" under the band name "DaiKichi". This movie is didn't fit the continuity while W take place after the final episode until Eiji used Tajadol Combo again. The character of Kamen Rider Birth made its debut in the films