This tweet says "92 protests in 44 prefectures throughout Japan", with the link to a site that lists them all. Most will likely be small, but who cares.
I took a look at IWJ's Aomori1 channel. A middle-aged man is making a speech on a street corner. People keep passing by. There are a few others who are with him. So? I'm watching. So are 34 others somewhere in the world.
Yasumi Iwakami's IWJ staff/volunteers will be at many of these locations to netcast live. If they are not there, someone else will use his/her smartphone and do it, I'm sure.
From IWJ's website (original is in Japanese):
▲▽▲▽ Protest at PM Official Residence, Friday August 31, 2012 ▽▲▽▲
6PM〜 8.31 Urgent! Stop Ooi Nuke Plant! Protest at PM Official Residence
CH5 1st Stage ＣＨ６ 2nd Stage ＣＨ７ in front of the DPJ HQ
▼ＣＨ８ 6PM Protest at US Embassy ▼ＣＨ８ 7PM Protest at the backside of PM Official Residence ▼ＣＨ８ 8PM Protest in front of LDP HQ ▼ＣＨ９ 5PM Save Children from nuclear war! Protest over Fukushima children evacuation lawsuit in front of Ministry of Education and Ministry of Finance ▼ＣＨ９ 6:30PM No! to "Nuclear Village" appointment! Minister Hosono should abandon the appointment! ▼ＣＨ５＋ＣＨ６ 8:15PM ８・３１No! to "Nuclear Village" appointment! Human chain in front of the soon-to-be Nuclear Regulatory Commission ▼Aomori1 5PM Friday action in front of Aomori Station ▼Iwate1 6:15PM Beyond Nuclear Friday Demonstration in Morioka ▼Fukushima1 6PM Follow the Friday Protest in Tokyo! No Nuclear Friday in Koriyama ▼Ibaraki1 6PM 5th Protest in front of Japan Atomic Power Co. Ibaraki Office ▼Gunma1 6:30PM Friday Protest against nuke plant restart at Takasaki Station West Exit ▼Saitama1 6PM Citizens' parade for zero nuke ▼Chiba1 5:30PM 2nd demonstration in Sodegaura City for decommissioning all nuke plants ▼Ishikawa1 6:30PM No Nuke Protest No.9 ▼Gifu1 6PM Beyond nuclear Gifu citizens ▼Aichi1 6PM Stop Ooi Nuke Plant immediately! Protest in front of KEPCO Tokai Branch ▼Osaka1 6:30PM August 31 anti-nuke protest @KEPCO HQ ▼Hyogo1 6PM Occypy in the Blue Moon 8.31 @KEPCO Kobe Branch
Oh yes, Friday's full moon is a blue moon.