When a character is lent from a first game device to a second game device, clocks of those two game devices are synchronized, a shared lending/borrowing expiration time is set, the use of the character is temporarily disabled in the first game device, and the use of the character is temporarily enabled in the second game device. Then, a character return timing is determined, based on a time of the clock and the lending/borrowing expiration time, in the respective game devices. In accordance with the determined timing, the use of the character is enabled in the first game device, and the use of the character is disabled in the second game device. Thus, it is possible to lend/borrow a character as an item in the real world without generating a copy thereof, and the lent character is sure to be returned at the expiration of a predetermined lending/borrowing period.