When a mobile terminal obtains a container upon movement of a display range, a processor increases points in a storage unit. When the mobile terminal opens a container obtained by movement of the display range or as a present from another mobile terminal, the processor opens the container at predetermined success percentages, and writes an item obtained from the opened container in the storage unit. When the mobile terminal presents a container without opening it, the processor transmits screen data indicating a present to the other mobile terminal. The processor converts an item in the storage unit into points to increase the points in the storage unit based on an operation of the user of the mobile terminal.