Yakuza 4

This trophy is based entirely on luck, but don't worry you do not need any experience or prior knowledge in Mahjong at all to obtain this trophy. In mahjong, you start the game by receiving 13 tiles, you draw 1 tile at the start of each turn and discard 1 tile afterwards. To unlock this trophy, you must win by achieving the hand of “Seven Pairs”. Japanese Mahjong Hand "Seven Pairs"

This means you need to have 7 different pairs to win (4 of the same tiles does NOT count as 2 pairs), which means you must not “Pung”, “Chow” or “Kung” at any point of the game.

Before you begin the game, you should change the match rules to the following so that the rounds last longer and you have more time to gather the necessary pairs.
* Match Settings - Half Game
* Kuitan - Not used
* 2 Fan requirement - Use
* Red dora - Not used

There are only 4 copies of each tile in the game. So, your basic strategy boils down to discarding any tiles that you have more than 2, as well as getting rid of the same tiles that your opponents discard so you don’t end up with dead tiles. When you have 6 pairs in your hand, there are 2 options: You draw the last tile to complete the 7th pair, press when the "Tsumo" prompt appears to declare a win; or someone discards the last tile you need, then and only then you can press when "Ron" prompt appears to take that tile he discarded and declare a win. Either option will unlock the trophy. This is what your hand should look like. If you're interested in knowing more about the game, see Beginner's Guide to Mahjong by barticle.

Video by desginedmusic (1:40 onwards)