1. An apparatus communicable with a plurality of client devices, the apparatus comprising: a storing unit configured to store a three-dimensional model and information that identifies a target position of a predetermined part of a user; a receiving unit configured to receive a request from at least one of a plurality of client devices and receive a measured position of the predetermined part of the user from a measuring unit that is configured to measure the position of the predetermined part of the user and that is included in the at least one of the plurality of client devices; a calculation unit configured to, in a case where the measured position of the predetermined part of the user is not the target position and is within a predetermined range of the target position, generate a representation of a movement of the three-dimensional model that corresponds to the target position and store the representation of the movement of the three-dimensional model that corresponds to the target position in a storage device; an obtaining unit configured to, in a case where the measured position of the predetermined part of the user is the target position after the calculation unit has stored the representation of the movement of the three-dimensional model that corresponds to the target position, obtain the stored representation of the movement of the three-dimensional model that corresponds to the target position; and a transmission unit configured to transmit the obtained representation of the movement of the three-dimensional model that corresponds to the target position to the at least one of the plurality of client devices for synthesis processing to be performed by a synthesizing unit included in the at least one of the plurality of client devices.