The Japanese Emperor was used as a tool by the military dictatorship during WWII and the government later used this narrative to launder his past and portray him as a post-war figurehead for the country. Similarly, figures like George Washington were also portrayed in an idealized manner in their respective countries.
The way historical figures are portrayed in textbooks and media is often idealized and not fully accurate, creating an unrealistic perception of these figures as superhuman.
Historian Herbert P. Bix suggests that the post-war investigation of the Japanese Emperor was to determine if he had the power to stop the war, and perhaps the government used the Emperor as a tool of the military dictatorship to wrap the modern state around his figure. However, the potential power of the Emperor seems to be greater than the reality of the situation.