Fukui Prefecture, with 13 commercial nuclear reactors clustered along a short coastline, had earned the area a reputation as a political stronghold for the atomic power industry before the Fukushima disaster, after which nuclear power was switched off in Japan.  Nuclear-friendly politicians dominated most of Fukui’s government offices, and the region is nicknamed Genpatsu Ginza, or Nuclear Alley.
Kansai Electric Power Company’s application to resume operation of two nuclear energy plants in Ooi in this region met strong protests and the regional court granted injunction against the operation in 2014. In the lawsuit, a group of 189 people from Tokyo, the plant’s host prefecture of Fukui and 20 other prefectures contended that the No. 3 and 4 reactors at the Oi plant had resumed operating in August 2012 even though their safety had not been certified, claiming that the plant is sited near several active seismic faults and is not adequately protected against earthquakes.  Kansai (KEPCO), they claim, underestimated the maximum magnitude of earthquake that the units could face. The court ruled in favour of the plaintiffs and issued an injunction against Kansai restarting units 3 and 4, which were undergoing safety assessments by Japan's Nuclear Regulation Authority (NRA) prior to restart.
At a press conference, NRA chairman Shunichi Tanaka noted that the court order applies to the restart of the reactors and not to the inspection process itself. He said, "We will continue with our examination ... as planned." Kansai said that it was disappointed with the court's decision but said that it would appeal the ruling in the high court.
An editorial in The Japan Times  noted that Prime Minister Shinzo Abe, in reversing the nuclear phaseout policy, had emphasized the economic viability and supply stability of nuclear energy. He dismissed the no-nuclear option in Japan’s energy mix as unrealistic, noting that the nation is losing trillions of yen each year due to the increased cost of fuel imports to run thermal power generators to make up for the shutdown of nuclear power plants. The Ooi court ruling of 2014 discarded however a similar argument by KEPCO noting that it is legally irrelevant to discuss people’s fundamental rights to life on the same level as the question of rising costs of generating electricity.
================================================== Following the shut down of all of Japan's reactors after the March 2011 accident at the Fukushima Daiichi plant, Ooi 3 and 4 had been given permission to resume operation in August 2012. The Japanese government announced that unit 3 (1180 MWe) reached full capacity in the early hours of 9 July, becoming the first Japanese reactor to restart following suspension for periodic inspection since the March 2011 Fukushima Daiichi nuclear accident. Its sister unit, Ooi 4, was expected to follow later that month. On June 7, 2012, about 70 women including 10 women from Fukushima had done a "die-in" in front of the Prime Minister's Official Residence to protest against the restart of Ooi Nuclear Power Plant. Before the "die-in", 10 Fukushima women visited the Cabinet Office and met with officials to submit a letter of requests addressed to Prime Minister Yoshihiko Noda. Journalists reported, "It’s raining there. But a group of protesters against the restart of the plant has been facing the Fukui riot police in front of the entrance gate... Right now, the protesters are drumming and shouting “Saikado Hantai (no to restart)”. Buddhist nun / writer Setouchi Jakucho joined hunger strike to protest against restarting Ooi nuclear plant. She became 90 years old on 5/15/2012. Her doctor warned her it could be fatal, but she joined without informing her doctor of it. She says, she can not die while leaving the country killing people with nuclear power.
============================================== In a parallel case, in 2015 a district court ordered the closure of two reactors switched on again after the 2011 disaster. The reactors to be closed were Kansai reactors at the Takahama nuclear plant, about 350km west of Tokyo, not far from Ooi. It was the second time Judge Higuchi had issued an order forbidding a nuclear plant in Fukui to operate. He became a hero among antinuclear activists in May 2014 when, as explained above, he ruled that two reactors at another Kansai Electric facility, the Ooi nuclear plant, must remain switched off because the utility had not shown that they could be operated safely.
However, after further court rulings, by 2016 Kansai Electric had hoped to restart Takahama and aimed to restart the No. 3 and No. 4 reactors at the Oi nuclear plant in 2017, although further injunctions could happen. There was a strong debate raised by Kunihiko Shimazaki, former acting chairman of the NRA. Shimazaki pointed out that Kansai Electric Power Co. underestimated the maximum shaking that could occur during an earthquake at its Ooi Nuclear Power Plant.
Update. - In fact, regarding the Ooi reactors, on July 4, 2018, a high court ruled thatthese two nuclear reactors at should not suspend operation, overturning a lower court ruling in favor of local residents who claim the plant is vulnerable to major earthquakes and other disasters. The ruling by the Kanazawa Branch of the Nagoya High Court on the Nos. 3 and 4 reactors of Kansai Electric Power's Oi plant came after the Fukui District Court ruled in May 2014 against their restart in the first such ruling over Japanese nuclear power plants since the Fukushima nuclear crisis in March 2011.
The pressurized water reactors in question already resumed operation in March and May 2018, respectively, after clearing in May last year new safety standards introduced in the wake of the meltdowns at Fukushima Daiichi power plant triggered by a major earthquake and ensuing tsunami.
The reactors had been idle since Sept. 2013 for regular safety inspections. They previously halted operations in March and July of 2011, respectively, for inspection and restarted in July 2012 after clearing provisional safety standards.