Every few months, I have the same nightmare: A major earthquake strikes Tokyo when my kids are at school. The city is in ruins. There's no electricity, the phones are out and the trains have stopped. I run through the streets, unable to find my children, until I wake up in a cold sweat.

The last time I had the dream, I went to my kids' school to find out what would happen if a major earthquake hit. Would the teachers keep the children at school? Or would they move to the neighborhood hinanjo (evacuation area), a large park near our apartment?

The vice principal was reassuring. He explained the various ways the school prepares, including the monthly hinan kunren (disaster drills), in which students learn what to do if the building starts to shake. They are taught to get under their desks to protect their heads, then grab their bosai zukin, a padded hood that doubles as a seat cushion. Not all schools require them, but every child at our school has one.