A management apparatus stores pairs of copyrighted contents and numbers of permitted check-outs. On being requested to perform check-out for a semiconductor memory card, the management apparatus records an audio object (AOB) corresponding to a content in the semiconductor memory card, assigns a content ID to the AOB, and decrements a corresponding number of permitted check-outs. An editing and playback apparatus plays back the AOB recorded in the semiconductor memory card. The editing and playback apparatus edits the AOB and assigns a content ID, which is the same as the content ID of the original AOB, to each new AOB obtained by the editing. A local storage holds history information including a media ID and the content ID assigned to the original AOB. On being requested to perform check-in for the semiconductor memory card, the management apparatus sets, in a non-playable state, the AOB assigned a content ID that is the same as the content ID in the history information and increments the number of permitted check-outs.