An example of an information processing system includes a vibrator. The information processing system is configured to store a frequency model function representing a model of vibration frequency transition, wherein the frequency model function includes, as variables thereof, a frequency variable representing a frequency for a period in the model and a period variable for that period. The information processing system is configured to determine a value of the frequency variable and a value of the period variable. The information processing system is configured to generate vibration information representing a vibration pattern that is defined by a frequency transition obtained by applying the value of the frequency variable and the value of the period variable to the frequency model function. The information processing system is configured to control vibration of the vibrator based on the vibration information.