The Social Democratic Party on Friday announced a draft for legislation that would redress wartime victims claiming compensation from the government.
The draft would enable the government to set up a council to investigate wartime damage inflicted on victims, such as Korean and Taiwanese residents in Japan, who served in the Imperial Japanese Army as soldiers or civilians.
It also urges the government to clarify its responsibility to redress victims of wartime acts through investigations.
"The government has neglected to take proper measures to redress the victims," SDP chief Takako Doi told a news conference. "The SDP plans to ask for support from other parties and hopes to submit the bill during the next Diet session."
Meanwhile, the government reportedly plans to provide lump-sum compensation to South Korean residents of Japan who were drafted into the Imperial army.
Chief Cabinet Secretary Hiromu Nonaka has said the government is willing to take sufficient steps to redress those wartime victims "within this century."
A 1951 pension law for soldiers and civilians wounded in war disqualifies non-Japanese as beneficiaries, such as Korean residents in Japan whose Japanese citizenship was stripped following the 1952 San Francisco peace treaty.
Koreans were forced to take Japanese nationality when Japan colonized the Korean Peninsula in 1910.
Under the law, the Japanese government has paid 40 trillion yen to war veterans and civilians who were wounded during World War II.
No compensation has been given to non-Japanese, except 30,000 Taiwanese soldiers who received 2 million yen each from Tokyo in 1988.
About 50 lawsuits have been filed across the country seeking compensation from the government for wartime suffering.
Although most claims have been dismissed, courts in many cases urged the government to legislate measures so victims could receive redress.