Here are some Shogi variants. #More_Games
Many of them should be playable with MOD64 pieces. Since the pieces move differently than chess pieces, I recommend changing the height of the pieces to remind you of the changes. For example, you can represent the silver general that moves one space diagonally or one space forward with a short bishop. You can think of the movement as: since the bishop is short, it can't move as far as a regular bishop.
The mechanic where pieces can switch sides can be implemented by simply switching out the color of the scarf on each piece.