There would need to be a much higher level of societal trust than there has been justification to have in much of the world today. Add to that Tokyo's situation

There would need to be a much higher level of societal trust than there has been justification to have in much of the world today. Add to that Tokyo's situation is built on a lot of suffering in silence. Tokyo is nice to visit, but the locals aren't nearly so keen. As a tourist you wouldn't see that so much. Of course that's not to say the world couldn't still learn a lot from the place. Besides, with many countries having children below replacement levels will such situations be necessary? Even for Japan perhaps not in the decades to come.