There were rumors of agitators at the June 29 protest at the Prime Minister's Official Residence in Tokyo where a great number of people (between 17,000 and 200,000, depending on who you ask) gathered to protest the restart of Ooi Nuclear Power Plant. There were also rumors of certain people behind the protest (certain large PR agency in Japan, for example).
Recently, there have been people who strongly advocate violence as a way to attract more attention to their anti-nuclear (or anti-Noda administration) causes. There are also people on Twitter who seek to remove certain "elements" from the protest (one of their target seems to be Mr. Kouta Kinoshita and his followers, for some reason). There are rumors that some of the organizers of the Tokyo protest are in favor of accepting and burning the disaster debris that are contaminated with radioactive materials.
Now, what may be a sign of radicalization is happening. Yomiuri Shinbun reports that a man was arrested on July 1 for trying to stab himself in protest against the restart of Ooi Nuke Plant.
From Yomiuri Shinbun (7/5/2012):
Knife-wielding man during the ant-nuclear protest, to stab himself in protest
It has been revealed by talking to persons whose duties involve investigation that the Metropolitan Police arrested a man on July 1 on suspicion of violation of the Swords and Firearms Control Law (illegal possession of a knife) on the scene of the protest against the restart of KEPCO Ooi Nuclear Power Plant in front of the Prime Minister's Official Residence in Chiyoda-ku, Tokyo. The man is exercising the right to remain silent.
According to our source, the man took out a fruit knife from the bag in front of the PM Official Residence in the evening of July 1. The riot police subdued him. The man allegedly said at that time, "I was going to stab myself in protest."
If such a thing actually happens, I think it will instantly turn off the majority of people protesting. This man could be a plant to split up the opposition to the restart of Ooi Nuke Plant, to nuclear power in general and to the Noda administration. He could well be genuinely frustrated enough to do what he said he wanted to do.
Protests being split up is not necessarily a bad thing, tweets this seasoned veteran on protests:
It is inevitable that some young people with too much energy get radicalized soon and resort to direct action. There will be cases where the senior members of TEPCO and Democratic Party of Japan are attacked. There will be people who will call these young people radicals and exclude them from the movement, which will then split into pieces. But that is OK. The movement should split up, and proceed with many, different intentions [or purposes] and in various formats.
We'll see. I am still hoping that Japan, having always been very good at adopting foreign ideas and products and improving on them, can somehow improve the way the "revolution" progresses, if it is a revolution they want.