According to one embodiment, a method includes writing, to a regular recording region of a tape medium after having written a first data accumulated in a buffer to a temporary recording region of the tape medium without an accompanying backhitch, a first data group that includes the first data that has any gaps between data eliminated, predicting a second volume of a second data, to be written in response to a command that is sent after the first data has been written to the regular recording region, judging whether the first volume exceeds a first threshold and whether or the second volume exceeds a second threshold, and writing the second data to the regular recording region without an accompanying backhitch when it has been judged that the first volume exceeds the first threshold and the second volume exceeds the second threshold.