The Shinto god of Fire, Kagutsuchi no Mikoto, was not a nice fellow: he burned his mother, Izanagi, to death while being born, so his father, Izanami, cut him into 8 pieces, which then became 8 major volcanoes of Japan. Izanami gave birth to the goddess of water, Mizuhane, during her death throes, and told her to pacify her brother and keep him under control.
Water and fire are yin and yang (or In and Yo in Japanese), and this comes into play in the tearoom a lot: for instance, we write the trigram for water on the ash in the bottom of the brazier where the fire is lit.
