To the casual observer, 95-year-old Lee Hak-rae could be just another elderly person in Japan. Surrounded by pictures of his family and paintings by his great-grandchildren, Lee potters about his cluttered living room on the outskirts of Tokyo.

But Lee is obsessed by brutal events of 75 years ago that have defined his life: his recruitment into the Japanese army from then-occupied Korea in 1942; his role in building the Thai-Burma railway; being designated a World War Two criminal; and how, he says, he was tossed into the dustbin of history by both Japan and South Korea.

Since recovering its sovereignty under the San Francisco Peace Treaty signed in 1951, and reviving military pensions in 1953, Japan has given a pension supplement that can add up to about $41,000 a year to military veterans.

That includes war criminals and their families, government officials say. Japanese wartime leaders convicted of war crimes by an Allied tribunal are honored at Tokyo’s Yasukuni shrine.

The treaty also meant Koreans who fought for Japan lost their Japanese nationality, and with it, entitlement to such assistance. More importantly for Lee, the men have never been afforded the attention and a sense of closure given to their Japanese counterparts.

"Listen to me. Why are they treating us differently?" says Lee, switching in a barely audible voice between Korean and Japanese.

"It’s unfair and doesn’t make any sense. How can I accept this unbelievable situation?” Lee said as he clutched dog-eared clippings documenting his years of campaigning for recognition and compensation.

Lee was among 148 Korean war criminals convicted after the war. Now he is the last survivor.

Twenty-three of them were executed and he too was sentenced to death by hanging as Kakurai Hiromura in 1947.

His sentence was commuted on appeal to 20 years. He was released on parole from a Tokyo prison in 1956.

About 240,000 Korean men took part in the war on the Japanese side.

After the war, the Allied governments rounding up suspected war criminals treated men of Korean ethnicity as Japanese. But the men were rejected by both Korea and Japan, historians say.

"The Koreans convicted of war crimes had a terrible time after the war because they were regarded as collaborators by other Koreans, but they weren’t recognized by the Japanese government as veterans," said Robert Cribb, history professor at Australian National University.

Cribb said it was unfair the Japan gave pensions to their war criminals but not to Koreans who were part of the Japanese army.

THE LIZARD

In 1943, Lee oversaw about 500 Allied prisoners of war (POW) building what later became known as the Death Railway between Thailand and Myanmar.

About 12,000 POWs died from overwork, beatings and exhaustion during the construction of the 415 km (258 mile) line. The conditions were made famous in the 1957 film "The Bridge on the River Kwai".

Trial records reviewed by Reuters show prisoners remembered Lee, known as the Lizard, as one of the most brutal guards on the railway.

Austen Fyfe, an Australian POW, said Lee was notorious for his brutality and beat him repeatedly, including with a bamboo stick on the back of the head. Other prisoners said Lee would stalk their makeshift hospital and "beat up the people he thought to be well enough to work".

Lee told the court he had "pushed them slightly near the shoulder" but denied charges of brutality, records show. Lee said Koreans were on the lowest rung of the Japanese military hierarchy and merely took orders.

After his release, Lee started a taxi company with other Korean war criminals. Afraid of being labelled a traitor back home, he felt he could not return, even missing his mother's funeral.

"Except my parents and siblings, no one would welcome me," he said.

In 1999, Japan’s Supreme Court rejected compensation claims by Lee and other Korean war criminals.

In 2006, South Korea recognized them as victims of Japanese imperialism but offered no compensation to those living in Japan. Those in Korea gained the right to subsidized healthcare.

Lee can now only walk with help but he keeps campaigning, even from his wheelchair. In June, he went to parliament to urge lawmakers to propose a law compensating Korean war criminals and their families.

"I was lucky to live until 95. I don't want to live longer for myself but I can't stop fighting for my dead comrades," he said.