1. A device, comprising: a reconfigurable circuit whose internal circuit structure is reconfigurable; a generation unit operable to generate circuit information that includes at least area information showing an unconfigured area in the reconfigurable circuit; a transmission unit operable to transmit, to a design data generation apparatus, (i) the circuit information generated by the generation unit and (ii) functional information showing a function to be established in the reconfigurable circuit after the reconfigurable circuit is reconfigured; a reception unit operable to receive, from the design data generation apparatus, design data for configuring, in the unconfigured area, a missing circuit that is necessary for configuration of a circuit that realizes the function to be established; and a configuration unit operable to cause the reconfigurable circuit to configure the circuit that realizes the function to be established based on the design data received by the reception unit.