The autumn fireworks at Omagari are not a competition. In August, this same riverbed hosts the contest that decides who makes the finest fireworks in Japan. Sixty thousand people, twenty-eight companies, a prize from the Prime Minister. In October, none of that. The local pyrotechnicians gather, choose a theme, and experiment. They call it sozo hanabi - creation fireworks - and Omagari is where it began. Shapes that refuse to be circles. Forms that have no name yet. Autumn air in Tohoku is clear in a way summer air never is. Colors arrive undiluted. Edges hold. A night when fireworks makers light the sky for each other.