King in Shogi
The King (Osho) is the most critical piece in Shogi, equivalent to the King in Chess. If your King is trapped (checkmated), you lose the game.
Originating from Chaturanga in ancient India, Japan uniquely split it into 'Osho' and 'Gyokusho'. Etiquette dictates that the higher-ranked player uses Osho, while the challenger uses Gyokusho.
Used in contexts like 'Checkmating the King' or 'Building a castle (defense formation) to protect the King'.
Which most critical piece in Shogi leads to immediate defeat if captured?