A notification system for notifying a user of information on driving of a bicycle includes a processor and a storage to store a computer program to control an operation of the processor. The processor is configured or programmed to execute the computer program to acquire traveling speed information representing a traveling speed of the bicycle, perform a first count operation of counting a time duration in which a first state of the traveling speed not being higher than a first predetermined speed, is continued based on the traveling speed information, and in a case in which the first state has been continued for a first predetermined time duration, notify the user via a notifier of first information indicating that the driving of the bicycle by the user has been appropriate.

An information processing device according to the present disclosure, detects that communication between a vehicle and a user terminal is established; and controls a notification unit included in the vehicle at a timing when the communication is established.

An information processing device according to the present disclosure, detects that communication between a vehicle and a user terminal is established; and controls a notification unit included in the vehicle at a timing when the communication is established.