A festival of boats, and a festival of fire. Osaka's Tenjin Matsuri is one of Japan's three great festivals, alongside Kyoto's Gion and Tokyo's Kanda. Its central figure is Sugawara no Michizane, the deity of learning. The highlight comes on July 25 with the boat procession, when some hundred vessels move along the Okawa River around the boat bearing the deity's spirit, bonfires reflected on the water, drums sounding from the decks. Then come the fireworks, around three thousand of them, blooming twice over, once in the sky and once mirrored on the river. The festival began in 951, more than a thousand years ago, to console Michizane's spirit and ward off calamity. Osaka is a city of water, threaded with rivers and bridges, so its festival, too, takes place on the water. Fire and water together, Osaka's summer spreading across the river.