A non-transitory storage medium stores a graph drawing program for causing a computer to execute acquiring a plot point of a first graph by a handwriting input, regressively calculating a plurality of graph data by a plurality of regression models, based the acquired plot point, performing first determination to determine, in regard to each of the graph data, whether at least a partial data element is included in a predetermined range of coordinates, performing second determination to determine graph data having a good regression accuracy among the plurality of graph data, selecting one of the graph data, based on a result of the first determination and a result of the second determination and drawing a second graph in place of the first graph, based on the selected graph data.