A state information storage (121) stores an observation position, an observation direction, and a base direction in a virtual space. Upon acceptance of an instruction input given to an external controller and indicating a moving direction, an observation position updater (112) updates the observation position so that the observation position moves in the moving direction indicated by the instruction input relative to the base direction. An observation direction updater (114) updates the observation direction in accordance with a change in orientation of a display apparatus (100) as detected by a detector (113). An obtainer (115) obtains a relative position between the controller and the display apparatus (100). A base direction updater (116) updates the base direction on the basis of the observation direction and of the obtained relative position.