It's a bit unclear to me why you need an organization that advocates against nuclear weapons. I'd argue the “nuclear taboo” is just the product of.. I don't just seeing one nuclear test video? It doesn't take the cataloging of witness testimony to see it's terror (though that may be important in its own right) I'm not intimately familiar with Japanese self-perceptions - but from the outside it seems like post-WW2 the…
The general human tendency to focus on single short term events seems to be the main cause. Let's compare using Wikipedia as a source: Atomic bombings in Japan: 50,000–246,000 casualties. Air Raids in Japan: 241,000–900,000 killed, 213,000–1,300,000 wounded, 8,500,000 rendered homeless. Mass killings of large civilian populations should not happen. I don't personally see nuclear weapons as worse than incendiary bombs…
* one early bomb is more or less equivilant to one conventional HE + incendiary raid.
* 2,000+ other bombs have since been detonated, a good number of which were orders of magnitudes more destructive than the early "first gen" bombs used on Japan.
Nuclear war with the larger weapons that followed would be considerably worse than incendiary bombs, in physical destruction, in immediate deaths, and in injuries and following mortalities.