There are entire manga/anime centered around Mahjong, like Saki and the multitude of spin-offs. And there's many more than just those.
replyIf you have a Nintendo Switch, Clubhouse 51 games includes a pretty decent Riichi Mahjong mode that'll explain all the rules too.
The kaiji author is a massive riichi fanatic if I recall correctly.
replyYes, he is! (Which explains other of his mangas, Akagi):
reply> He has been playing mahjong since junior high school days, and admitted that though he has rarely lost a game when he was in school, his current level of ability is average. According to him, he has "tournament luck" and has even won mahjong tournaments between mahjong manga artists. He has also participated in professional mahjong matches. He played about two games against Akagi and Kaiji's voice actor Masato Hagiwara, who is known as one of the best mahjong players in the entertainment industry, and made Hagiwara say "I don't think I can beat him."