1. A streaming distributing device for distributing streaming live contents comprising: circuitry to: generate a first fragment storing data of a content to be distributed by streaming; generate a second fragment storing a timed text markup language document instance relating to a subtitle to be displayed in said content; add, to header information of said second fragment, instance classification distinguishing information for distinguishing whether said timed text markup language document instance stored in said second fragment is a timed text markup language document instance specifying a rendering context relating to said subtitle; and store, in said second fragment, a sample in which said timed text markup language document instance is described, together with description content identifying information for individually identifying a description content of said timed text markup language document instance relating to said subtitle for distinguishing whether said timed text markup language document instance is an initialization document instance or a body document instance using flag information indicating true or false, wherein, only when said timed text markup language document instance is an initialization document instance, the sample includes an identifier indicating whether the initialization document instance is changed after the initialization document instance was generated.