If you look at a map of Kitasenju in Tokyo's Adachi Ward, you will see that it's almost entirely surrounded by water.
The Arakawa River to the north and the Sumida River to the south come together and run side by side, just a few hundred meters apart, then diverge before meeting again, like the outline of a python digesting an egg.
Kitasenju is the egg, and last Saturday I discovered how fragile a place it can be to live in. As the rain from Typhoon Hagibis threatened to cause the Arakawa to overflow and flood the whole area, my family and I found ourselves sheltering overnight in the local primary school, fearing that our house would be deluged.