The long and narrow space is divided into two sections, one front space painted in white and the other inner space painted in green. Those who come back from green space into white space will feel red light. This is because when surrounded by green light, one becomes more sensitive to red as a complementary color, so that one see white room as red room. This phenomenon is called persistence of complementary color, which lasts only for a second to be turned back soon into original white room. The space recalls the red light that used to be shining on this neighborhood Koganecho from the deep in the memory back to mind in a flash.