A playback apparatus plays back video data recorded on a recording medium such as a BD-ROM. The playback apparatus includes (i) an interface in which a removable medium such as an SDRAM is inserted, (ii) a detection module detecting that the removable medium is inserted, and (iii) a virtual file system. The virtual file system is used if the removable medium is detected to be inserted, if additional content such as subtitles is recorded on the removable medium, and furthermore if the additional content is associated with the video data recorded on the BD-ROM, etc. The virtual file system dynamically combines the video data recorded on the BD-ROM, etc. and the additional content of the removable medium so as to play back a virtual package.