In the process of establishing modern military and military education system, Japan inherited the spiritual tradition of feudal Bushido and instilled the idea of absolute respect for the emperor in the military. 1878, Yamagata Aritomo, Lieutenant-General and Minister of the Ministry of War promulgated Catch-21, which regards loyalty to the emperor as the first duty of soldiers and tries to instill the bushido spirit of "loyalty, courage and obedience" into soldiers. 1882, in the name of the emperor, the imperial edict was further promulgated, clearly stipulating that soldiers should be loyal to festivals, have correct manners, be brave, be faithful to justice and benefit, respect frugality, and must be "loyal to the monarch and patriotic" and worship the emperor as a "god".

The so-called bushido was originally the moral standard of feudal warriors, and loyalty to the monarch and patriotism was its foundation. It emphasizes the pride of fighting, promotes the spirit of self-sacrifice and is willing to serve the master. A warrior is martyred for the death of his master, or in order to save the humiliation caused by defeat, he must be brave enough to commit suicide by caesarean section to show his absolute loyalty to his master. In modern times, the Japanese ruling clique inherited this spiritual tradition, beautified it in every way, pretended to be the inherent spirit of the Japanese nation, and imposed it on the broad masses of soldiers and civilians, making the reactionary and barbaric spirit of militaristic Bushido more and more prominent and reaching an unprecedented level.