Tens of thousands are calling for no nuclear, but what is the alternative?

One man who only gave his name as Ozaki tells CNN, "If there is a power shortage, there are alternatives. What about coal-fired power stations, hydro-electric power stations, or we can just survive with what we have. We have to be patient, but even with blackouts, we can survive without nuclear power."

While the government can't help but hear these voices, it has managed to resist them so far. Two nuclear reactors were brought back online this month. All 50 reactors had previously been taken offline for maintenance and tests. The government's argument is simple: Japan needs power.

Read more: What Japanese leaders can learn from the Fukushima nuclear crisis

Prime Minister Yoshihiko Noda told the public last month: "In order to lead prosperous and decent lives, cheap and stable electricity is indispensable. Japanese society will not be able to function if there is a decision to permanently halt nuclear power generation."

Masami Hasegawa is a senior manager at Japan Business Federation and agrees that Japan faces an energy crisis heading into the hot summer months. Last year rolling blackouts adversely affected business, he says.

"We hear our members saying that they cannot stay in Japan if this situation continues," says Hasegawa. "If the current situation continues, energy consuming industries cannot survive in Japan and they will leave. The immediate effect will be on employment which might be lost."

But protesters say safety is more important, pointing to a recent parliament report which stated the Fukushima disaster was man-made -- a result of collusion between the plant operator, regulators and the government.

With tens of thousands of evacuees still waiting to hear when or if they can return to their homes near the plant, protesters say a no-nuclear Japan is the only acceptable result.