A copy computer includes a storage device which stores a copy of contents
from a distribution computer and a module which creates a copy of updated
contents based on a copy request and which sends a copy of contents
requested by a search computer to a distribution request computer. The
search computer includes a module which searches for a copy computer
storing the copy of the contents requested by the distribution request
computer, a module which forwards a send request to a specified copy
computer, and a module which sends the copy request and the copy contents
to a predetermined copy computer when the contents are updated. The copy
request gives an instruction to create the copy of the updated contents
in the storage device of the copy computer.