There is provided an authoring method including the steps of generating a first materialization file not including material data itself and referencing a recording position of the material data to mount a first real image having a stream data structure of a first file system, the first file system including time-division multiplexed material data, generating a second materialization file not including material data itself and referencing a recording position of the material data to mount a second real image having a stream data structure of a second file system, the second file system being different from the first file system including time-division multiplexed material data, and arranging the first materialization file and the second materialization file under a directory of a first virtual image to generate the first virtual image.