Mini Shogi (1970)

This Shogi variant was invented (or, perhaps, rediscovered) by Shigeo Kusumoto in 1970. It is played on a 5x5 board and features pieces from standard shogi (king, gold, silver, bishop, rook, pawn). Pieces promote on the final rank. It also makes use of the standard shogi drop rule. Although played on a small board, mini shogi has not been solved, and it can serve as a simple introduction to shogi.