A mobile terminal apparatus receives a setting reference value set of plural setting items for an image forming apparatus from a management server, and transmits it to the image forming apparatus using near field wireless communication. The image forming apparatus determines a setting item of which a current setting value is different from the setting reference value, and transmits through the near field wireless communication to the mobile terminal apparatus adjustment item data that indicates the determined setting item, the setting reference value and the current setting value. The mobile terminal apparatus displays the received adjustment item data, and transmits through the near field wireless communication to the image forming apparatus an adjustment instruction that indicates a setting value of a setting item specified by a user in the adjustment item data. The image forming apparatus changes a setting value in accordance with the received adjustment instruction.