A shogi board was a 9×9 grid with 81 squares, divided into one's own camp (the three ranks closest to oneself) and the enemy camp (the three ranks closest to the opponent).
There were eight types of pieces in total (before promotion), with twenty pieces per side.
King/Gyoku (1): moved one square in any direction.
Rook (1): moved any number of squares in a straight line.
Bishop (1): moved any number of squares diagonally.
Gold General (2): moved forward, forward-left, forward-right, left, right, or backward (but not diagonally backward).
Silver General (2): moved forward, forward-left, forward-right, backward-left, or backward-right (but not left, right, or directly backward).
Knight (2): moved only in an L-shape (jumping two squares diagonally forward, able to leap over pieces).
Lance (2): moved any number of squares straight forward (unable to retreat).
Pawn (9): moved one square forward.
In Japan, shogi's rules looked similar to Chinese chess at first glance, but they were actually somewhat different.
This was because certain pieces could be flipped over and promoted after entering the enemy camp (the opponent's three ranks), such as a Rook becoming a Dragon King or a Bishop becoming a Dragon Horse, gaining enhanced movement.
After a Rook promoted to a Dragon King, it gained the ability to move one square diagonally in addition to its original ability to move any number of squares straight.
After a Bishop promoted to a Dragon Horse, it gained the ability to move one square straight in addition to its original ability to move any number of squares diagonally.
It was also because of this special rule.
That in a shogi game, once the Rook and Bishop had both promoted, it was common for the entire board position to undergo a dramatic upheaval.
After Natsume Chikage and Furukawa Ayuo arranged the pieces.