Reverend Akira Sato dreams of hearing hymns echo once again through the church he was forced to leave behind after the Fukushima Daiichi nuclear disaster a decade ago.

Ten years after a tsunami overwhelmed the cooling systems at the nearby plant, sending it into meltdown, the Fukushima First Bible Baptist Church is a shell haunted by memories.

"In the past when I've come back here and looked around, I couldn't stop my tears from falling," Sato said on a visit to the church in Okuma town, five kilometres (3 miles) from the crippled plant.

It lies in the approximately two percent of Fukushima prefecture that is still a no-go area because of radiation.

Visitors need permission to enter, and must wear plastic suits covering their body and bags over their shoes and hair before they go in.

At the church, which once hosted a congregation dozens strong, time has stood still.

A notice for a Sunday mass that was never held is still posted on a billboard at the steel entry gate. Above sit a damaged cross and a rusty bell.

Inside, a ray of sunshine illuminates empty pews.

The silence is shattered only by the alarm from a Geiger counter indicating radiation "hotspots" in the house of worship.

The steep-roofed church is surrounded by vast vacant lots belonging to neighbours forced to destroy homes that were rendered uninhabitable by the earthquake or radiation.

Inside the chapel, several bibles and hymn books sit on a podium next to an organ that has not been played since the disaster.

The 63-year-old reverend was outside Fukushima when the earthquake struck, and it fell to pastor Masashi Sato to shepherd dozens of the church's faithful away from the Okuma church.

"I evacuated carrying just a few bottles of water and the Bible," said the pastor, who is not related to the reverend.

Departing the region, he felt he was living "a tribulation sent by God."

"I was asking God: 'Why did this happen? What does this mean? What will happen to us?'" the 44-year-old told AFP.

After the disaster, most of the flock decided to stick together.

Reverend Sato joined them and they embarked on a year-long exodus -- moving from Aizu in western Fukushima to the Yamagata region, down to Tokyo and then eventually settling in the Izumi district of Iwaki city.

Their final destination was just 50 kilometres from the church they had left behind, but they travelled over 700 kilometres before settling there.

One parishioner was killed in the tsunami and several died after the evacuation. Others suffered discrimination over rumours that people from Fukushima could "infect" people with radiation.

Harumi Mottate, an 83-year-old church member, recalls the time as "a test".

"It was a turbulent year," Mottate, who was evacuated on a military truck, told AFP.

"I was deprived of my daily life in Okuma all of a sudden. If I had not had faith, I would have resented what happened to me."

Christians are estimated to account for just 1.5 percent of Japan's 126 million residents, most of whom practice a mixture of Shinto and Buddhism.

Communities are dotted across the country, and the Fukushima church's history dates back to 1947, when an American Baptist missionary emigrated to the region, eventually establishing a small congregation.

The displaced parishioners held their first mass at the new church in Izumi in 2013, and their congregation now includes new members.

Hiroshi Hiruma, 84, joined the new church after being forced to abandon his contaminated home in the town of Tomioka near Okuma.

"I thought Tomioka would be my final hometown, but there is nowhere to go back anymore," said Hiruma.

"Even if I wanted to go back, I can't."

He has now settled into life in Izumi, in part thanks to the new church, a modern building with stained glass windows.

Dozens of Christians fill the pews during services, reading Bible passages and singing hymns accompanied by a piano and organ. The warmth and community offers a stark contrast to the lonely emptiness of the old church.

"I've gotten used to this place," Hiruma said after a recent Sunday mass.

"This is my final abode."

Reverend Sato had also once considered ending his journey in Izumi but now feels he is still only halfway home, and wants to return to Okuma.

"I may build a hut and spend the rest of my life there," the grey-haired reverend said.

"Appreciating every word of the Bible and holding heartwarming and humble hymn gatherings: those are my dreams for the future."

He won't be able to return permanently until at least next year, when authorities plan to lift restrictions after decontamination in the old church's neighbourhood. But he is hopeful.