A man driving a minicar attempted to ram a motorcade carrying Emperor Akihito and Empress Michiko on Friday morning in Hokkaido.
A police motorcycle escort, however, blocked the car's path, and the Imperial Couple were unharmed, police said.
The Imperial Couple's car was damaged in the right front when the minicar hit one of the motorcycles. The motorcycle was knocked over and struck the Emperor's car.
The incident occurred on a two-lane road, police said. The driver of the minicar, Osamu Koizumi, attempted to pass the tail of the motorcade from behind and ram the Imperial Couple's car.