A non-transitory computer readable medium stores a program causing a computer to execute a process. The process includes: obtaining plural items of writing information including writing position information and writing timing information, each of the plural items of writing information being associated with one page of one document; displaying an image in accordance with plural items of writing information associated with an identical page among the obtained plural items of writing information; receiving a specified writing timing; updating a display mode of the displayed image in accordance with the received writing timing; and changing an association between at least one of the plural items of writing information corresponding to the displayed image and a document, based on the received writing timing.