Compared to his Majesty's army, Nazi Germany army behaved like gentlemen. Nazi Germany basically only targeted Jews and at least killed them as human beings. His Majesty's army targeted eveyone and killed people as killing animals.
His Majesty the Emperor of Japan can only assuage the soldiers to behave professionally and to fight the enemy in a proper way. There were over 9 million sons of Japan who fought in the war and their actions were their own. Perhaps we can attribute some brutality due to indoctrination and the environment wherein they fought. War can affect the judgment of even the most civilized and behaved of us.
At the same time The Emperor Showa cannot be too stern on the memory of His soldiers who gladly died in His name. For His honor. This is why we have to understand the special bond the memory of the sons of Japan had to the Emperor, to the Emperor's last breath in this earthly realm.