A notification system includes an acquirer configured to acquire acceleration of a vehicle and an operation state of a direction indicator, and a controller configured to cause an output unit to output a notification for prompting a user to suppress the acceleration of the vehicle in a case where the acceleration is equal to or more than a first predetermined value, the controller not performing the notification in a case where the acceleration is equal to or more than the first predetermined value and information that makes it possible to recognize that the direction indicator is operated is acquired.