Washizu Mahjong

It plays like Riichi Mahjong, but needs a whole different set of tiles. 1/4 of the tiles are opaque and 3/4 are translucent. So, the strategies are a lot different since you may see about 3/4 of the tiles in your opponents hand. Variant from the Manga Akagi, and there are sets made exclusively to play this particular variant of the game.