The Sendai High Court on Wednesday ordered the state and the operator of the crippled Fukushima nuclear plant to pay 1 billion yen ($9.5 million) in damages to residents over the 2011 tsunami-triggered disaster.
It was the first time for a high court to acknowledge the state's responsibility for the incident in about 30 similar lawsuits filed across Japan.
The amount the Sendai court told the government and Tokyo Electric Power Company Holdings Inc. to pay to 3,550 plaintiffs was up from the sum of 500 million yen that a lower court ordered them to pay to some 2,900 plaintiffs in an October 2017 ruling.
The government will review the ruling before deciding how to respond to it, Chief Cabinet Secretary Katsunobu Kato told a press conference.
In line with the 2017 ruling by the Fukushima District Court, the high court made its decision based on three points in dispute, including whether a major tsunami could have been foreseen.
The two other points were whether countermeasures could have been implemented to prevent a disaster, and whether the compensation levels outlined by the government were sufficient.
The plaintiffs had sought monthly compensation payments of around 50,000 yen per person until radiation at their residences returns to the pre-crisis level, bringing their total final demand to approximately 28 billion yen.
The state, meanwhile, argued it was impossible to predict the tsunami and prevent the subsequent disaster. Tepco claimed it had already paid compensation in accordance with government guidelines.
In the district court ruling, the government and Tepco were both blamed for failing to take steps to counter the huge tsunami caused by an earthquake.
It ruled that the two should have been able to foresee the risks of a maximum 15.7-meter-high wave, based on a quake assessment issued in 2002, and that the disaster could have been prevented if the state had instructed the operator to implement measures that year.
The magnitude-9.0 earthquake and ensuing tsunami struck northeastern Japan on March 11, 2011, causing multiple meltdowns and hydrogen blasts at the nuclear power plant.
Around 55,000 people remained evacuated both within and outside Fukushima Prefecture as of the end of August.