@pdonk
He was fighting in the tournament to get scouted as a rep-player to pay for Hanako's overseas operations.
He was able to make enough for him and Koume with gambling alone.
You can't win off a tile you have dealt yourself before.
You can't win off a tile which was dealt by someone else that turn and you passed on it.
So if a turn passes you can win off that tile you have passed on before.