A data reproduction apparatus and a data storage medium for synchronously reproducing multiplexed data with video, audio, and superimposed dialogue data compressed at a variable rate and performing various functions. Data are reproduced from the data storage medium using sector numbers, and data for negative sector numbers carried by some sectors are also reproduced. Multiplexing information indicating whether or not image, voice, and superimposed dialogue data is each multiplexed and information for the positions of access points used for data search and random access are stored in the positions represented by these negative sector numbers and reproduced so as to enable multiplexed data with video, audio, and superimposed dialogue data compressed at a variable rate to be synchronously reproduced and various functions to be executed.