DRIVING ASSISTANCE DEVICE, VEHICLE, AND DRIVING ASSISTANCE METHOD

A driving assistance device is provided. An acquisition unit configured to acquire data regarding a travel trajectory of another vehicle from the other vehicle by vehicle-to-vehicle communication. A specifying unit configured to specify an intersection position between the travel trajectory of the other vehicle and a travel trajectory of a self-vehicle based on the data acquired by the acquisition unit. A selection unit configured to select data for setting a region based on the intersection position and the travel trajectory of the other vehicle as a monitoring region when performing driving assistance in a case where the intersection position is specifiable by the specifying unit. The selection unit selects data that has been partially deleted from the data acquired by the acquisition unit based on the intersection position.