In the summer of 2012, tens of thousands of people gathered around the prime minister's office with one message — no more nuclear power. People flooded the streets of Tokyo's Nagatacho district, chanting and holding up signs saying "No Nukes!" in the hope their voices could be heard.

It is a moment historical sociologist Eiji Oguma has captured in his debut documentary film, "Tell the Prime Minister," which will start screening at Uplink cinema in Shibuya on Sept. 2.

"This movement is extremely important for the modern history of Japan — even the world," Oguma says. "I had been following the demonstrations and I knew that I wanted to record it someway or another."