Just one solution for this problem.

The game functions like chess, with 2 notable exceptions :

• Pieces taken from your opponent can be reused and placed (almost) anywhere on the board in place of moving a piece inside the board (that is why they have a directional shape and are all the same color). It is also allowed to check-mate your opponent by dropping a piece on the board (except with a pawn, for some obscure reason).
• Most pieces have a promotion, a bit like the pawn turns into a queen when reaching the last row. In Shogi, pieces are promoted when making a move on the board that enters, leaves or moves inside the last 3 rows opposite to you (your opponent’s camp). The Rook gains the ability to move 1 square diagonally (x shape) and the Bishop gains the ability to move 1 adjacent square (+ shape). The other lesser pieces convert to a Gold General. Only the King and the Gold General cannot be promoted.

The concept of dropping pieces taken from the opponents exists in a 4 player variant of persian chess where 2 teams of 2 play each other, each team has a black and a white player, and anything taken by the white player from their black opponent is given to their black teammate, who can use it on their own board, and vice versa.

Edit: made the explanation a bit clearer