An input assistance device includes: an operation unit configured to accept information selected by a user from a plurality of input candidates; a storage unit configured to store a priority for displaying the plurality of input candidates according to a display order, the priority determined based on an input history of information accepted by the operation unit in association with each of the plurality of input candidates; and a control unit configured to refer to the storage unit, to change the display order of the input candidates determined based on the priority into other display order by replacing a first input candidate among the plurality of input candidates in a first range from a top percentile priority with a second input candidate in a second range that is outside of the first range, and to output the plurality of input candidates according to the other display order.