Akagi (2015) Native title: アカギ
Akagi Shigeru is a young, white-haired mahjong genius. One summer in 1965, he ends up facing off against Washizu Iwao, Japan’s King of Darkness who has amassed enormous fortune and power, at the request of his acquaintance, the rogue detective Yasuoka. As the observer, Ogi Takeshi, a leader of the henchmen of Inada-gumi watches over them, mahjong with special rules called Washizu Mahjong begins. It is a life or death struggle withAkagi’s fresh blood and Washizu’s entire fortune at stake. (https://mydramalist.com/15079-akagi)
OAL while i liked it, explaining the rules of the game got old (i used me apps during that time) but the suspense of who was going to win kept me watching.
Found at: Crunchyroll