General Mahjong Info/Review
Rather than put my money earned in Yakuza 0 at risk, I thought i'd practice here to get a preliminary understanding of the game first. I'll post some helpful links to anyone who is curious to learn. Its tricky in and of itself. But its pretty satisfying now that i've won a few rounds and got the hand of how to do it: https://en.wikipedia.org/wiki/Japanese_Mahjong#General_mahjong_rules

Basically you are stealing tiles to complete simple straights (chi) from the player who went last turn on the left of you, and collecting pairs to wait for a 3 of a kind to get discarded from any other player that you can steal when its your turn (pon). You can also draw three tiles (no stealing) and save them over time to go for a four of a kind instead (kon) This requires some patience and time and is harder to do than it seems.
https://psnprofiles.com/guide/5892-yakuza-0-mahjong-completion-guide

It helps to have a reference of the tiles, like this, because the sequence matters:

Mahjong Taikaii II Review
This game itself is kind of neat. It's built around the premise of a kind of tourney ladder, every new game has new 'personalities' of famous people. There are more and they are random on each time you turn the game on.What honor it will be to spar in a parlor with the great General George Washington!

Now the thing about Mahjong is there are lots of variations, and its a more chaotic game than it looks in terms of adaptive strategy. This particular game is based around Japanese Mahjong I believe, the game does feature at least some of the japanese twists such as Dora/flipping over second Dora, but I'm unsure about some of the other scoring methods (Bu and Fu) or special hands I read about. These things might be toggle-options in the game (but I don't know because i'm not a reader of japanese) and that is okay as far as I am concerned because it's all a bit much to a beginner. When the player can perform a steal the rival tile flashes, but if you can play a Kon, you have to tell the AI you want to do that by pressing the D-Pad down and choosing the right option.
The game seems amusing. When you perform moves or things happen the animated portraits of the characters react with glee, indignation or disbelief. Its a shame I can't read the text. The game is quite playable though if you read a bit about how J-Mahjong works.

One interesting aspect of this game that is worth mentioning is that once all 144 tiles of a set are shuffled for a round, they are in a certain sequence which will then be 'dealt/flipped' this means that there is zero randomization or chance to how the tiles come out. Often in card/board/gambling games its random and % what happens. Combine this with the way Mahjong operates by a round often lasting with a whole 'deck' being distributed and you have something a bit interesting about this game in terms of learning Mahjong. On an emulator you can use save states or rewind to 'practice' a round to see what would happen if you did any possible move:
First, you learn how chaotic the game is and how the decisions of a player affect the game. Second, you learn about how you can alter the sequence in which that sequence or distribution takes place by stealing for example (A big part of Japanese Mahjong is how you want to try and grab the very last tile for extra han (points) using it as a qualifying move (Yaku) to finalize your hand. Third you learn how defensive discard works by seeing what the AI discard and how you should be discarding like products or similar products. Four, you learn a bit about how scoring works by being given examples of what the outcomes were for a round (particularly how bad it hurts when a player shouts 'Ron'! and snatches the tile you discard to trounce you.) Depending on how other Mahjong games actually work in distributing tiles, this aspect of the game (While unlikely to be intended for the reason in which it is useful) may matter significantly as it is definitely a better design for learning the game with the ability to cheat.

In terms of accessibility. It seems it is not easy to find that many Mahjong games that are the J-style (not solitaire, not chinese, or some other derivative) that are in English. Typically that isn't the sort of thing people make translation patches or would bother to make localized versions of. I googled and found some options but this one was free and accessible enough to learn the basics before giving a go at it in Yakuza 0.