One day while playing a game, Shinnouske and his friends discover a theatre. While they were about to watch it, Shin-chan wanted to go to the washroom. When he returned, all of his friends were not there, which at first, made him think that they had gone back home without him. But back home he found out that none of his friends had returned home. He tells his parents about the theatre and they all decide to go to the theatre. The Nohara family leave their dog, Shiro in the house and leave. When they reach the theatre and watch the film, they are taken away by a bright flash of light and find themselves in the Old West of America. Soon they find that they are a part of the film.