History storage device, image forming apparatus and non-transitory computer readable medium storing program

A history storage device includes: a storage unit that, in storing first history information including phenomenon information corresponding to a phenomenon having occurred and accompanying information accompanying the phenomenon information in a storage region, when the phenomenon information included in the first history information is duplication of phenomenon information included in second history information having already been stored in the storage region, deletes the phenomenon information included in the first history information and stores, in the storage region, the accompanying information which is included in the first history information and is associated with the phenomenon information; and a reconstruction unit that, in reading out the first history information from the storage region, based on the phenomenon information with which the accompanying information included in the first history information is associated, reconstructs the deleted phenomenon information, to thereby reconstruct the first history information including the phenomenon information and the accompanying information.