What is "renju"

Renju (Japanese: 連珠) is the professional variant of Gomoku. 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.

Renju eliminates the "Perfect Win" situation in Gomoku by adding special conditions for the first player (Black).