Japan's Chiba District Court ruled on 22 September that Tokyo Electric Power Company (Tepco) should compensate losses caused to local residents who were forced to leave their homes after the 2011 Fukushima disaster. The lawsuit, which was filed by 45 defendants in March 2013, sought total compensation of JPY2.8bn ($25m).

Kyodo news agency said the focus of the case was whether the government and Tepco were able to foresee the tsunami that devastated the NPP in 2011, and to take preventive measures, with conflicting claims made by the parties regarding the government's long-term earthquake assessment, which was made public in 2002. The  assessment, by the government's earthquake research promotion unit, predicted a 20% chance of a magnitude-8-level tsunami-triggering earthquake occurring along the Japan Trench in the Pacific Ocean within 30 years, including the area off Fukushima. The plaintiffs argued that the tsunami could have been predicted and that the disaster was preventable if emergency power generation equipment had been placed on higher ground. They further argued that the government should have made Tepco take such measures by exercising its regulatory powers.

The government and Tepco said the assessment was not established knowledge, and that, even if they had foreseen a tsunami higher than the site of the plant and taken measures against it, they could be held liable as a massive tsunami of around 15.5 metres. The government also argued that it obtained regulatory powers to force Tepco to take anti-flooding measures only after a legislative change following the disaster.

Judge Masaru Sakamoto was quoted by NHK as saying that Tepco “did not entirely fail to adopt measures against the risk of tsunami” and that “it cannot be considered as gross negligence” However, “the psychological sufferings of local residents over losing lives and the community they used to have are related to the accident, and Tepco should compensate”.  Tepco was ordered to pay compensation worth more than JPY376m to 42 of the 45 plaintiffs, but the court did not hold the government responsible for the accident. "Although the government was able to predict the possibility of a tsunami higher than the site of Fukushima NPPs unit 1 reactor by at least 2006, even if it had introduced safety measures, this would not necessarily have prevented the accident," Sakamoto said.

This was the second such ruling involving the Fukushima disaster. However,  in the first ruling last March, the Maebashi District Court in Gunma Prefecture found both Tepco and the government responsible for the nuclear disaster and ordered them to pay a compensation of JPY38.55m to 62 plaintiffs.