The Japs have always been in serious denial about their various horrific acts, from far history to the recent, like the Rape of Nanking, Pearl Harbor, and the Bataan Death March.
They don’t much talk about Hiroshima, either...
But in reality, only white liberal nations wallow in guilt over their past national crimes. No other group of people on earth does this. Muslims don't. Africans don't. Native Americans don't.
In the liberalized West, we're very accustomed to obsessing over our past sins. We think our sins are uniquely evil and we thus don't usually expect non-Western people to fret over their own violent pasts. To the liberal mind, sins by non-Western people could never possibly reach to level of wickedness of Western sins. However, we treat the Japanese as a bit of an exception (i.e., it upsets us a little when they ignore their past crimes) because we consider them to be a first world nation, so we expect them to be “just like us” and spend a great deal of time fretting about their past.
Japanese history is fascinating to me, perhaps especially because of their blend of the highest art, culture and sensitivity with the most incredible brutality and bestiality.
Such things have always existed in every society, but as far as I’m aware the Japanese are nearly unique in their ability to combine these in the same person, indeed almost at the same time, without seeing a conflict.
For example, the Japanese Army was well known in the Russo-Japanese War and WWI for being chivalrous and well-behaved. By the time WWII came around, the extreme opposite. A good many have tried to attribute the change to Nazi influence. But a cursory study of the period will show the Japanese didn’t really pay all that much attention to the Nazis.
The answer, IMO, is that the brutality of WWII as compared to earlier wars of the century was merely a different aspect of the Japanese military tradition coming to the fore. They were both there all the time. The only difference was which one was in the ascendant.