A control unit creates caption management data having plural caption texts to which caption display times each indicating a time of starting reproduction of each caption text are added and plural images in association with one another in accordance with a reproduction order, and stores the caption management data in a memory unit. The control unit selects a caption text registered in the caption management data, and acquires received caption display times of the selected caption text and a caption text corresponding to the next reproduction order. The control unit sets the caption display time of the selected caption text as the initial value of a dummy caption display time. When determining that a difference between the initial value and the caption display time of the caption text corresponding to the reproduction order next to the selected caption text is larger than the reference time, the control unit stores a time acquired by adding a predetermined time to the initial value and a dummy caption in the memory unit in association with each other.