A video playing system, which plays video data divided into a plurality of blocks, includes: a delivery part that delivers video data, a playing part that plays the delivered video data, and a detection part that detects viewing speed of the video data at a start point of a block of interest, at an end point of the block of interest, and at a point between the start point and the end point of the block of interest. When the detected viewing speed satisfies a predetermined condition, information indicating that viewing for the block is completed is generated.