A robotic Abe bows in apology for Japanese war crimes (at a Shanghai robotics show)

So why did Germany apologize after World War II and work so hard to show that it was truly contrite (sorry, regretful) for all of the horrible things it had done during the 1930s and 1940s?

My guess is that during the domination (extreme control) of the Nazi government in Germany (from 1933 to 1945) there were many Germans who still opposed (were against) Hitler and even secretly fought against him and his government.  When World War II ended, some of these Germans took control of the German government. Since they had never been 'real' Nazis themselves, it was easy for them to say that Germany had done horrible things and to openly apologize and admit to all the war crimes and crimes against humanity of those years.

I am not sure there was much of a resistance in Japan during World War II (resistance would mean an organized movement of people against the government). Also, the Emperor was allowed to remain in office after the war. I am assuming that the Japanese who took control of the Japanese government after WWII had supported the war and the policies that occurred under Hirohito's reign. The worst Japanese war criminals were executed by the US military (killed by the military) but the people who took office in Japan had probably supported the war and the war-time government. 

I think this helps to explain why Germany went out of its way to admit the truth about WWII and apologize for starting it. China and Korea are still upset with Japan to this day for, as they see it, not following suit (not doing the same thing as Germany). 

This lingering (lasting) anger toward Japan can be seen at a robotics show in Shanghai, where someone has created a robot of Japanese Prime Minister Abe bowing to apologize for what Japan did during WWII. 

The article:

https://www.hongkongfp.com/2015/07/15/robot-of-japanese-pm-bows-in-apology-to-china-at-shanghai-exhibition/

Vocabulary from the article:

to bow - this means to bend one's body forward from the waist as a sign of respect or sorrow or regret

atrocities - war crimes, horrible things done by soldiers in a war

a stiff smile - an unmoving smile, a tense smile, a smile that doesn't change

presumed - guessed, assumed

to ridicule someone - to make fun of someone, to make it seem as if someone is foolish

China is set to - China is ready to

to mark - to remember

However, Japanese Chief Cabinet Secretary Yoshihide Suga said a press conference on Monday Abe has not received such an invitation. correction: However, Japanese Chief Cabinet Secretary Yoshihide Suga said in a press conference on Monday that Abe has not received such an invitation.