1. A system for composing a pictorial/video image content where FIU (face image which the user designates) is reflected, comprising: an input/output device; a DCU (pictorial/viDeo image Contents where the FIU is reflected) production control module installed in an information processing device having an operation system for storing and managing information related to a source pictorial/video image content, for outputting and operating a production guide window, and for performing an overall control over changing a face of a specific source character appearing in the source pictorial/video image content to an FIU pattern; an REU creating module for converting, under the control of the DCU production control module, a representative expression image of a specific source character appearing in the source pictorial/video image content into one matching with the FIU, to create an REU (Representative Expression image for User design character); an SEU creating module for converting, under the control of the DCU production control module, standard expression images of the source character based on conversion features between a representative expression image of the source character and the REU, to create plural SEUs (Standard Expression images for User design character); an EDU creating module for selectively combining and transforming the SEUs, under the DCU production control module, based on conversion features exhibiting when a proximate expression image that is most proximate to each reproduced expression pictorial/video image of the source character among standard expression images of the source character is converted into each reproduced expression image, to create an EDU (Expression pictorial/viDeo image for User design character); and a DCU creating module for creating, under the control of the DCU production control module, a DCU having a face image of the source character being newly replaced into the FIU pattern by combining the EDU with a background of the source pictorial/video image content, wherein the REU creating module comprises: an REU creating control section for performing an overall control of an REU creating procedure; an FIU loading section for loading the FIU, under the control of the REU creating control section; a salient point designation guide section for displaying, under the control of the REU creating control section, the FIU having been loaded by the FIU loading section through the production guide window, to designate a salient point at a main part of the FIU; and an REU creating engine for estimating, under the control of the REU creating control section, positions of vertexes that constitute a polygon mesh of the REU on the basis of a difference degree between a position of a salient point designated at the main part of the FIU and a position of a vertex that constitutes a polygon mesh of the source character representative expression image, and for converting the positions of the vertexes constituting the polygon mesh of the source character representative expression image into positions of the vertexes constituting the polygon mesh of the REU, thereby creating a REU matched to the FIU.