A multi-projection system configured to display output frames as a single screen by display frames displayed by display devices, respectively, the system includes a screen position setting unit that sets output frame position data that is data of position of each of the output frames in the single screen when synthesizing the output frames to the single screen, and display frame position data that is data of position of each of the display frames in the single screen; an output frame obtaining unit that obtains output frames; an output frame synthesizing unit that synthesizes the output frames based on the output frame position data; a display frame generating unit that generates the display frame for each of the display devices using a part of the synthesized image based on the display frame position data; and display units that display the generated display frames, respectively.