To reliably protect the confidence of a document to be formed and outputted on a sheet.

In an image formation system 1, when a printer engine 12 forms an image on a sheet provided with an information-writable RFID tag on the basis of image data, a CPU 26 causes an RFID reader and writer 13 for reading and writing information by communication with the RFID tag of the sheet to read characteristic information stored in the RFID tag, associates original image data of the image formed on the sheet by the printer engine 12 with the characteristic information of the sheet, and transmits the original data associated with the characteristic information from a network I/F 21 to an image log server SV.