 New actor Shintaro Morimoto and new actress Marino Kuwashima were officially revealed as the lead cast members of this film at the film's 10th press conference on 11 May 2009. They were handpicked from a group of 10,000 people in an audition by director Joji Matsuoka. Matsuoka reportedly decided to choose Shintaro and Marino because they "had a different twinkle in their eyes". In particular, Shintaro, the younger brother of Hey! Say! JUMP member Ryutaro Morimoto, was praised by the director, who said that he was looking for a child "who can exist for real". Matsuoka described Shintaro's qualities as "rare nowadays", and also described him as an "angel".
