The civil war in Japan called "Hougen no ran" began as a result of parent-child quarrel between the former emperors of Toba-in and Sutoku-in.
The civil war is a major explosion centered on the battle between Emperor Go-shirakawa and Sutoku-in brothers.
It is the grandson of a monster politician Emperor Shirakawa, who likewise laid the political system called Insei.
Emperor Toba hated and eliminated his son due to inferiority complex to Emperor Shirakawa. This will cause a great disturbance bisecting Japan.