Drop-off assistance device and drop-off assistance system

The drop-off assistance device includes: a sensor for detecting an object behind the vehicle; a communication device capable of communicating with another vehicle; a notification device for notifying an occupant of the vehicle; a sensor; a communication device; and a controller connected to the notification device, wherein the controller detects a rear vehicle located behind the vehicle based on a detection result of the sensor at the time of parking and stopping the vehicle, establishes communication with the rear vehicle in response to the detection of the rear vehicle, and causes the notification device to notify the presence of the approaching object in response to the communication device receiving the detection of the approaching object to be notified from the rear vehicle.