'There were two groups. I asked one to stay at the top of the building and the other at the bottom of the building for a little while. They started to read their books and some of them talked about their books with others. Later they started moving towards the staircase. Why two groups: one going up and one going down? It reflects the postdisaster situation in Japan – falling apart into two groups, one that says we still need nuclear power and the other that says we don’t. I tried, symbolically, to mix up two extreme groups'