Renju (Japanese: 連珠) is the professional variant of Gomoku, a strategy board game originating in Japan from the Heian period. It was named Renju by Japanese journalist Ruikou Kuroiwa (黒岩涙香) on December 6, 1899 in a Japanese newspaper Yorozu chouhou (萬朝報). The game is played with black and white stones on a 15×15 gridded Go board.