The premiere will air sometime in 2024. You can check out the PV here. This adapts a manga series called Touhai that ended its run in 2011, but it also has a huge web of sequels and spinoffs, some of which are still in publication. Below I included the AniList synopsis of the manga:

Not a lot of people know that one of the most talented and ruthless Mahjong players in the city is a young high school boy. Kei is a teenager of few words, but his observation skills, unwavering will and experience in the game allows him to survive in a world full of powerful, rich and dangerous characters. Kei is currently hiding a girl named Amina who has entered the country illegally and protecting her from being deported. He spends his days sleeping through class and his nights playing high stakes Mahjong, waiting for when a worthy opponent arrives.