The fun of a game is increased, and the player can be induced to play the game repeatedly. Belonging group determining means determines that the prefecture to which a player character belongs is Osaka Prefecture, belonging group variable determining means determines that the enthusiasm rank parameter of Osaka Prefecture is “normal”=0 points, belonging group event result determining means determines the result of a predetermined event with respect to the player character, and belonging group variable varying means varies the enthusiasm rank parameter of Osaka Prefecture according to the result of the predetermined event with respect to the player character.