A few points:
* Not all Japanese forces were brutal and cruel. Japanese rule in a few places was mild and tolerant. It depended on which general was in charge in the country.
* Many Japanese leaders opposed harsh and cruel measures when they became aware of them, and many Japanese leaders did not learn of the army's cruelty until after the war because of army censorship.
* The death rate of Japanese POWs held by the Soviets was nearly double the death rate of American POWs held by the Japanese.
* We killed hundreds of thousands of Japanese civilians, many of them women and children, in our bombing raids on Japan. The numbers of dead and wounded grew even more when we began to use napalm ("fire-bombing"). After November 1944, Japan was virtually defenseless against air attacks. Our air raids lost fewer than 4 percent of their planes.
* FDR, desperate to save Stalin's Soviet Union from collapse, imposed increasingly harsh sanctions on staunchly anti-communist Japan and rejected every Japanese peace offer. Japan only decided to attack Pearl Harbor when it became clear that FDR was not going to accept any of the enormous concessions that Japan was offering in an effort to get the sanctions lifted. Instead of making Japan an ally, FDR provoked them to war. Japan was prepared to invade the Soviet Union, but FDR made sure that didn't happen.
http://miketgriffith.com/files/immoraluse.pdf
Oh my, those poor Japs, abused by Da Ebul FDR; I guess he also sent them training films on the correct use of pitchforks for loading live babies onto trucks and other Fun Facts of Japanese occupation. All those American POWs were liars, too, forced to perjure themselves by Da Ebul FDR, too. Stalin told him what to do n stuff.
Cherry-picking and exaggeration don't refute facts. FDR definitely pushed the Japanese into war because he was desperate to save Stalin's Russia. He turned down very reasonable, if not extraordinary, Japanese peace offers, and refused to even meet with Prince Konoye (Konoe) to discuss the situation.
As for Japanese occupation, go read Hildi Kang's book
Under the Black Umbrella: Voices from Colonial Korea, 1910ā1945. Kang interviewed hundreds of Koreans who lived under Japanese rule in Korea and was rather stunned to discover that most of them had never experienced cruelty and that quite a few of them said they had no problems with the Japanese. Yes, there were some cases of abuse and cruelty, but these were the exception, not the rule.
Or, read General Elliott Thorpe's book
East Wind, Rain. Thorpe was certainly no cheerleader for the Japanese, far from it, but even he was willing to admit that the Japanese treated Dutch prisoners from Java better than Sukarno's thugs treated them.
You mentioned American POW accounts. Yes, go read those accounts, because some of them mention Japanese guards who were not cruel or vicious and who did what they could to help the POWs. I again repeat the fact that the death rate among Japanese POWs in Soviets hands was nearly double the death rate of American POWs in Japanese hands.
To be clear, I am not denying that in many cases, many Japanese soldiers behaved in a cruel, vicious, inhumane manner, but such conduct was by no means universal.
And, while we're at it, we might wanna consider the voluminous evidence that many American soldiers behaved in a cruel and inhumane manner as well, including extracting gold fillings from live Japanese prisoners, executing Japanese prisoners, and shooting at Japanese sailors in the water after their boats had sunk. Our soldiers did not commit as many war crimes as did the Japanese, but they committed quite a few. Read John Dower's famous book
War Without Mercy and Richard Aldrich's award-winning book
The Far Away War: Personal Diaries of the Second World War in Asia and the Pacific.