Ephemeral: a tatami laid on park lawns in spring, a parasol shading grain from the heat, an autumn screen, a snug winter coat for bare trees. Fixed with nails, rope, moorings or glue, found everywhere in city and countryside alike, its handsome azure dots the landscape of the Japanese archipelago. The Japanese call it Ao Ba, "the blue leaf": a tarpaulin whose quiet, functional presence Bertrand Desprez and Claire Dé follow across the country as an unlikely thread running through everyday Japanese life.