Men dressed as white herons wade into the stream, their wings outstretched, moving with the deliberate slowness of something ancient. Tsuwano is a castle town that time has been gentle with — narrow lanes, whitewashed walls, carp gliding beneath the road. The Sagi-mai is its midsummer offering. Not a performance so much as a prayer, repeated each July for centuries, addressed to no one in particular and everyone at once.