1. An image forming system comprising: a transmitter apparatus that transmits, to a predetermined storage location of a plurality of storage locations, identification information identifying a user and image data associated with the identification information; and a plurality of image forming apparatuses, each of the plurality of image forming apparatuses including: a first storage unit that stores storage information indicating the plurality of storage locations; a storage location that is included in the plurality of storage locations and stores the identification information and the image data associated with the identification information, the identification information and the image data being transmitted from the transmitter apparatus; a retrieval unit that accesses the plurality of storage locations indicated by the storage information stored in the first storage unit, when the identification information is inputted by the user, and retrieves the image data from the storage location; and an image forming unit that forms an image corresponding to the image data retrieved by the retrieval unit, wherein the transmitter apparatus and the plurality of image forming apparatuses are connected via a first communication line, each of the plurality of the image forming apparatuses further comprising a storage controller that retrieves, from a second image forming apparatus which is newly connected to the first communication line, storage information indicating a storage location of the second image forming apparatus when the second image forming apparatus is newly connected to the first communication line, and causes the first storage unit to store the retrieved storage information.