The traditional way to decide who is the sente (the first to play) and gote is making the furigoma. Traditionally, in chess the way to decide black or white is to take a pawn of each color and hide it in the hand and let the rival choose.
On important professional games usually is a helper who is in charge of do it, if there is no one else usually is the person with higher rank who does it.
The first minister of Japan doing the furigoma for the denousen tournament.
Should take the five pawns from the central columns and shake it strongly before throw it over the board. For important games usually there is a piece of cloth on the floor for this purpose. If the number of paws with the face 歩 is bigger than the paws with と the player whose pawns was taken will be sente. Otherwise, will be gote.
Furigoma means in japanese to shake the pieces.
Furu 振る shake
Koma (goma) 駒 piece