[Mouri makes the first move despite having the white pieces. It's a good thing Bruce isn't familiar with the rules.

He places a pawn on the grid, near the corner]

It is easy. You may place your pieces on any intersection on the grid. The main objective is to claim as many territories as possible.

[Mouri is forced to use some of the leftover chess pieces to simulate white pawns]

If you surround your opponent's piece from all sides like this the piece is out of the game.

That is the basic gist of the game.

[He thinks. He has never explained the rules of Go before]