Momotaros's Summer Vacation is a short film that debuted between the Gekiranger movie and I'm Born!. Using live action photographs, 3D computer graphics, and traditional animation (all of which is termed a Momotion Picture, it has Momotaros gloating of his strength until Sha-Fu dared him to proved it by swimming. After being made fun of by Urataros and Ryutaros, and bashed by Kintaros, Momotaros is talked into believing he can swim by Deneb. But as the "mind over matter" influence wears off, the Imagin and Sha-Fu tell the audience the movie's coming up soon.

Source: Wikipedia

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Other: Kamen Rider Den-O: Imagin Anime