A game device receives from another game device through a network calculation data. The calculation data includes, at least, position data which represents a position of an object operated by using the other game device, and time data which represents time in which the object is at the position. The game device calculates, based on the position data and the time data included in the received calculation data, a calculated position of the object as of when the calculation data is received. Further, the game device determines, based on the calculated position, a position of the object in a game space as of when the calculation data is received.