A scenario editing device comprises a scenario supplementing unit supplements
a
scenario memorized in a scenario memory according to a scenario basic rule memorized
in a scenario rule memory when it receives additional data set from a receiving
unit. The scenario supplementing unit includes a material represented by the additional
data set with multimedia contents to make the multimedia contents approach a complete
state. To receive the additional data set at the receiving unit, the scenario editing
device exhibits the multimedia contents with a incomplete state on a computer network.