Kubota, 26, was detained in July near an anti-government rally in Yangon along with two Myanmar citizens and jailed for 10 years.
A source at Japan’s embassy in Myanmar told AFP they had “been informed that Mr. Kubota will be released today” by junta authorities.
Kubota would leave for Japan “today”, they added.
Kubota is the fifth foreign journalist to be detained in Myanmar, after US citizens Nathan Maung and Danny Fenster, Robert Bociaga of Poland and Yuki Kitazumi of Japan — all of whom were later freed and deported.
At least 170 journalists have been arrested since the coup according to UNESCO, with nearly 70 still in detention.
“WE WILL BE MORE THAN HAPPY”
Families and friends hoping their loved ones would be included in the amnesty gathered outside Insein prison in Yangon, said AFP reporters who also saw several yellow buses enter the sprawling compound.
San San Aye said she was waiting for her brothers and sisters to be released.
“Three of them were sentenced to three years each eight months ago,” she told AFP.
“Their children are waiting at home. We will be more than happy if they are released.”
Kyaw Htay said his son had been sentenced to three years for sharing anti-coup posts on social media.
“I hope he will be released today,” he told AFP.
“Professor Turnell’s release is remarkable news after being held hostage by the regime, and his family and friends will be delighted,” independent analyst David Mathieson told AFP.
But he said the junta “shows no sign of reform and a mass amnesty doesn’t absolve them of atrocities committed since the coup”.
“Thousands of people jailed since the coup in Myanmar have done nothing wrong and should never have been imprisoned in the first place,” said Amnesty’s regional office spokesperson.
Three former ministers from Suu Kyi’s ousted government and detained US-Myanmar citizen Kyaw Htay Oo would also be released, the junta official said.
The military’s crackdown on dissent since it ousted Suu Kyi’s government has left more than 2,300 civilians dead, according to a local monitoring group.
The junta blames anti-coup fighters for the deaths of almost 3,900 civilians.
