1. A scenario generating apparatus that automatically generates a scenario for animation from an input sentence, the scenario generating apparatus comprising: an input for entering the input sentence into the scenario generating apparatus; an input sentence analyzer that analyzes a meaning of a word written in the input sentence and to which category the word corresponds; a scenario generator that generates a scenario using the analysis result of the input sentence analyzer; a scenario editor that edits the scenario generated by the scenario generator using information anticipated from a term in the scenario, wherein the anticipated information is acquired from the term in the scenario using external information associating the term with the information anticipated from the term; an external information acquiring knowledge storage that stores external information acquiring knowledge, comprising a combination of a type of the external information and acquiring source information relating to an acquiring source of the external information, wherein the external information is acquired using the external information acquiring knowledge stored in the external information acquiring knowledge storage; and a communicator, connected to a network, for controlling network communication with the scenario generating apparatus.