A position detection system 1 identifies position information on the basis of a position signal received from a storage medium 30P disposed in a placement area where a target item is placed, identifies item information on the basis of an item signal received from a storage medium 30Q attached to the target item, and associates the position information with the item information and stores the associated information when the item signal is received during a period of time that starts from a time at which the position information is identified and that does not exceed a predetermined length of time.