Japanese Occupation of Malaya  (Now known as Malaysia)

Two Japanese officers, Toshiaki Mukai and Tsuyoshi Noda competing to see who could kill (with a sword) one hundred people first. The bold headline reads, "'Incredible Record' (in the Contest To Cut Down 100 People—Mukai 106 – 105 Noda—Both 2nd Lieutenants Go Into Extra Innings".

Chinese prisoners being buried alive.

This grinning Japanese soldier holding a severed head is participating in the massacre that followed the fall of Nanking (now Nanjing). Japanese troops were encouraged by their officers to invent new and hideous ways to slaughter Chinese civilians and prisoners of war after the fall of the capital. This photograph was smuggled out of China.

Soochow, China, 1938. A ditch full of the bodies of Chinese civilians, killed by Japanese soldiers.

Shiro Ishii commander of Unit 731. The Americans allowed him to walk away free - despite his horrendous crimes against helpless Chinese victims at Unit 731
which experimented on human beings.

Japanese inhumane treatment of the Chinese during the Japanese invasion of China is well known. These are well documented so our younger generation should not forget.
What is Japanese attitude to war crimes and their inhumane treatment of the Chinese? It is summed up in the following testimony by Uno Shintaro, a former Japanese Army officer who served in China:
The major means of getting intelligence was to extract information by interrogating prisoners. Torture was an unavoidable necessity. Murdering and burying them follows naturally. You do it so you won't be found out. I believed and acted this way because I was convinced of what I was doing. We carried out our duty as instructed by our mastersWe did it for the sake of our country. From our filial obligation to our ancestors. On the battlefield, we never really considered the Chinese humans.When you're winning, the losers look really miserable. We concluded that theYamato race [i.e., Japanese] was superior”: Haruko Taya Cook & Theodore F. Cook, Japan at War 1993 ISBN 1-56584-039-9, p. 153; https://en.wikipedia.org/wiki/Japanese_war_crimes.  
This same mindset was in those same brutal military people who went toMalaya at the end of 1941 [NOTE: Second Sino-Japanese War (July 7, 1937 – September 9, 1945]. Many of them had just permanently left their savage ‘signature’ marks on China.
Just as we cannot forget the Japanese “Rape of Nanking”, their brutal and inhumane treatment of civilian victims (many of whom were Chinese) in Malaya is a part of history we cannot and should never forget. From glimpses of individual accounts, they were not only ‘war crimes’.[1] Many were acts of the most sadistic, horrific and inhuman kind.
What I would like to focus on here are some specific waves of Japanese war crimes inflicted on Malayan and Borneo people and westerners (Allies). These are:
    1)    The massive massacre of Chinese in Singapore and Malaya  
    2)    The Alexandra Hospital massacre in Singapore
    3)    The massacre of tribal Suluks  in Borneo,
    4)    The death march from Sandakan to Ranau,
    5)    The burning of Sandakan and massacre of Sandakan Chinese  
    6)    The West Kalimantan killing fields

1)    Sook Ching massacre This was theKempeitai’s systematic killing of thousands of Malayan Chinese following the start of Japanese occupation of Malaya. Within days of taking full control of Malaya (and Singapore) many groups of Chinese civilians were hunted by Japanese secret police (Kempeitai).[2] This was with one simple objective – to exterminate them as if they were nothing more than unwanted rats. This turned out to be a massive massacre (known as Sook Ching.[3] It was a purge of the Chinese population in various towns of Malaya and Singapore.[4]
Following their victory at Singapore, the Japanese are believed to have rounded up and killed thousands of ethnic Chinese civilians. Being Chinese was then perceived as being hostile to the new Japanese regime.[5] It seems, even in December 1941, an extermination list had been drawn up of key elements within the Chinese population.[6] For many Chinese, especially those on the list for executions, being on the run was for a long time about survival on a day-to-day basis.[7]
The following extracts are from an account by Lee Kuan Yew in his Memoirs, “The Singapore Story”.[8]
On Feb' 18, the Japanese put up notices and sent soldiers with loudspeakers around the town to inform the Chinese that all men between the ages of 18 and 50 were to present themselves at five collection areas for inspection.
The much-feared Kempeitai went from house to house to drive Chinese who had not done so at bayonet point to these concentration centres, into which women, children and old men were also herded.
I discovered later that those picked out at random at the checkpoint I had passed were taken to the grounds of Victoria School and detained until Feb 22, when 40 to 50 lorries arrived to collect them. Their hands were tied behind their backs and they were transported to a beach at Tanah Merah Besar, some 10 miles away on the east coast, near Changi  Prison. There, they were made to disembark, tied together, and forced to walk towards the sea. As they did so, Japanese machine-gunners massacred them. Later, to make sure they were dead, each corpse was kicked, bayoneted and abused in other ways. There was no attempt to bury the bodies, which decomposed as they were washed up and down the shore. A few survivors miraculously escaped to give this grim account. The Japanese admitted killing 6,000 young Chinese in that Sook Ching of Feb 18-22, 1942. After the war, a committee of the Chinese Chamber of Commerce exhumed many mass graves in Siglap, Punggol and Changi. It estimated the number massacred to be between 50,000 and 100,000.”
Hirofumi Hayashi, a professor of politics at Kanto Gakuin University and the Co-Director of the Center for Research and Documentation on Japan's War Responsibility, writes that the massacre was premeditated, and that’s because "the Chinese in Singapore were regarded as anti-Japanese even before the Japanese military landed."[9] Japanese also knew many Chinese people in Malayahad financially supported China in fighting to drive off the Japanese invasion and occupation of their motherland.[10]
The actual number of Chinese people killed in Sùqīng Massacre is not known. Estimates[11] range from 25,000 - 50,000 in Singapore and Malaya. It is not just the number of people killed. In the words of Professor Hirofumi,[12] “… even ex-Kempeitai officers involved have admitted that the killings were inhumane and unlawful”.[13]
During the Singapore Chinese Massacre Trial in 1947, Japanese army commanders identified Colonel MasanobuTsuji as the man responsible for the massacre.  He was the Chief Planning and Operations Officer of the 25th Army. He had close links with the Imperial Headquarters in Tokyo and enjoyed certain privileges that officers of more senior ranks were not allowed. It was he who had issued the orders.[14] He was never punished for his war crimes.
2) Massacre at Alexandra Hospital After the Japanese brutally mowed down the C company of the Malay Regiment[15] at Bukit Chandu[16], they went into a frenzied slaughter of people in Alexandra hospital.[17] It began at about 13:00 when the Japanese went into the Alexandra Barracks Hospital.[18] There a British lieutenant walked towards them with a white flag raised in his hand. He was instantly killed with a bayonet. As put by professor Gin Ooi Keat:[19] “… the Japanese soldiers went on a frenzied killing spree, bayoneting everyone in sight, regardless of whether they were medical personnel or patients”.The Japanese soldiers’ slaughter of helpless and horrified patients, doctors and nurses is to be remembered as though they were like humans slaughtering chickens at a chicken farm.
The following is a detailed account given by Jeff Partridge, a PhD candidate at Alexandra Hospital:[20]
Terror in the Operating Theatre For Captain Smiley and his colleagues in the operating theatre, it had been an exhausting day. The surgical team had continued operating throughout the barrage of shells and bullets. One of the Japanese platoons climbed into the verandah between the operating theater block and the surgical wards, firing into the corridor. The surgical team tried to carry a patient from the corridor into the operating theater, but were prevented by a hail of bullets that thudded against the walls. Captain Smiley approached the doorway and pointed to the Red Cross on his arm, but took cover when a shot whizzed past him and struck Private Lewis in the shoulder.
A Japanese soldier entered the room and found the men standing together in the middle of the floor with their hands above their heads. He motioned the men into the corridor. There a dozen Japanese soldiers set upon them with bayonets. Dr Rogers was stabbed in the right side of the chest and two more times as he lay on the ground. Dr Parkinson, who tried to run around the corner into the main corridor, was gunned down. McEwan and Lewis were killed by bayonet. The patient in the theatre, who was under anesthetic, was bayoneted to death on the operating table.
Captain Smiley received a thrust in the breast, which was deflected away from his heart by a cigarette case in his pocket. He blocked the next thrust with his arm and took the dagger in his groin. The next two thrusts severely injured his right arm and hand. Captain Smiley fell onto Private Sutton, who had thus far escaped attack. The Captain told Sutton to fall down with him and pretend to he dead. After the soldiers left. Private Sutton dressed Captain Smiley’s wounds. Both lived to tell of this event.
In another part of the hospital, the Japanese were busy assembling a group of more than 200 surrendered men. They were hospital staff and walking wounded, some of them in splints and bandages and hobbling on casts. Their hands were tied behind their backs and they were then tied into groups of eight. These groups were led out of the hospital by the north wing. A group of about sixty officers and men gathered from the upstairs area joined this larger group.
The prisoners were herded along the railway tracks, past the burning Normanton oil tanks, through a drain tunnel under the railway embankment to the Ayer Rajah Road, then to a row of buildings a quarter of a mile from the hospital and set about fifty yards back from the road. Men who were too weak to walk were allowed to lay their arms on the shoulders of more able-bodied men. But those who fell were bayoneted and left for dead. As fighting around the hospital was still intense, the prisoners were also subjected to the shelling of their own army.
The prisoners were packed into three small rooms, the biggest of which measured approximately 10 feet by 12 feet. Each room was crammed with 50 to 70 men. The doors were barricaded with lengths of wood and the windows shuttered and nailed up. There was no ventilation. The men remained tied together, but managed to take turns sitting on the floor to rest. A number of men found it possible to untie themselves and others, but there seemed no way out of the building short of a miracle. The men were forced to relieve themselves where they stood. All were thirsty, and many severely dehydrated. Some became delirious and slipped into unconsciousness. A number did not survive to see morning.
The following morning, a Japanese officer opened the door of one room and said in broken English, "We are taking you behind the lines. You will get water on the way." When the Japanese began taking the men out two-by-two along the courtyard and around the latrine, the prisoners’ hope for air and water brightened. More than 100 men were led on the water march. Soon the prisoners left behind began to hear screams of anguish, and cries of "Oh my God," "Mother," "Don’t, don’t." The sight of a Japanese soldier wiping the blood off his bayonet confirmed their worst fears: the prisoners were being systematically massacred. 08/03/01”
This gruesome incident has been listed as amongst the top 10 Japanese atrocities from World War II.[21]
3) The massacre of Suluks in Borneo TheKempeitai also committed brutal atrocities (Crimes against humanity) against ordinary other people.  Most notorious were their slaughter of natives in Borneo.
After a failed revolt by a group known as Kinabalu Guerrillas,[22] the Japanese set about to severely punish civilian populations. Hundreds of civilians were tortured after being arrested by them. It began in February 1944 when the Japanese searched the nearby Borneo islands looking for a leading Chinese resistance member. Through torture of a Dr. Lou Lai, they learned that the Suluks (a native group in Borneo) had participated in the uprising led by the Chinese man. This led to what resembles a sort of ‘ethnic cleansing’ (eradication of the Suluks).[23] The Japanese had targeted the Suluks for eradication. Those on the Mantanani Islands[24] were hunted down and slaughtered.  
In Jesselton Japanese soldiers first rounded up 58 Suluk men from the Mantanani islands and put them through unspeakable tortures. Thereafter, true to their style, they killed the victims. Two days after that, they massacred two other groups ofSuluks, one consisting of women and men. One group was shot dead by machine guns. The other group consisted of 4 children and 25 women. These were ordered to be machine gunned by Lieutenant Shimizu. These hapless victims were first rounded up and lashed together with ropes to a Mosque.[25] They were then shot to death with machine guns.[26]  Suluk houses were also burned down; these murderers were on a slash-n-burn routine.
Only 125 Suluks in Mantanani Island and 54 of the 120 in the Suluk population inDinawan Island[27] survived the massacre. All their men had been killed.[28] The Japanese also slaughtered 54 people out of the Suluk population of 114 on Sulug Island.[29] Suluks' houses were also burned down after the people had been machine-gunned. The Suluks were described as "virtually wiped out”. The Tokyo war crimes trial index described these Japanese atrocities as "an apparently systematic attempt to exterminate the Suluk race between February and June 1944". [30]

Note.  War is evil, we should not forget the history and should pass on to our next generation.