To provide a game device having a character transformation function and in which prevention of unnatural display of change of posture and facial expression of a character object is realized while suppressing increase in an amount of data and an amount of work related to motion data. In the present invention, a skeleton part (joint or bone) which is set for a character object placed in a virtual three-dimensional space is rotated so that a position of a predetermined vertex of the character object changes from a first position to a second position. In the present invention, a player is guided to change at least one of the first position and the second position. In a case where at least one of the first position and the second position is changed by the player, the position of the skeleton part is corrected so that the position of the predetermined vertex of the character object changes from the first position to the second position in a case where the skeleton part is rotated by a predetermined angle (S103, S104).