Shogi (将棋 shōgi, generals' chess) is also known as Japanese chess. It is a two-player board game in the same family as International chess, and Chinese Xiangqi. Shogi is the most popular of a family of chess variants, and is native to Japan. Shōgi means general's (shō) boardgame (gi). In early years, however, shogi was written 象棋 (the same as Xiangqi, "elephant chess").
The earliest predecessors of the game, chaturanga, originated in India in the 6th century AD, and spread from China to Japan, where it spawned a number of variants. Shogi in its present form was played as early as the 16th century, while a direct ancestor without the "drop rule" was recorded from 1210 in a historical document Nichūreki, which is an edited copy of Shōchūreki and Kaichūreki from the late Heian period (~1120).
According to ChessVariants.com, "Perhaps the enduring popularity of Shogi can be attributed to its 'drop rule'; it was the first chess variant wherein captured pieces could be returned to the board to be used as one's own. This has the consequence that few games are drawn, which is a weakness of international chess. David Pritchard credits the drop rule to the practice of 16th century mercenaries (ronin) who switched loyalties when captured—no doubt as an alternative to execution".