Provided is an image forming system for pull printing and does not need a server. A division part generates a blockchain of a document data by generating identification information of the document data for pull print, by dividing into blocks, and by calculating and including a previous hash value of a previous block in order. A storing and transmitting part transmits each of divided blocks. A storing part that stores received block. An outputting and transmitting part transmits the stored block according to the instructions. An identification information acquisition part acquires the identification information of the document data. A block acquisition part acquires each of the block of the document data corresponding to the identification information. A document reproduction part packs each of the block and reproduces to the document data. An image forming part outputs the document data.