At the time of manufacturing a DVD to be provided to a rental agent, a provider device writes an agent-rental expiry along with contents onto the DVD. At the time of renting the DVD to a user, a rental agent device writes a user-expiry onto the DVD. A DVD player acquires a current time from a time source device, and compares the current time with each of a prior time, the agent-rental expiry, and the user-rental expiry. The DVD player plays back the content only when playback conditions are met.