Shinohayu: the Dawn of Age
シノハユ the dawn of age
A prequel to the Saki series, focusing on Shino Shiratsuki, a young girl with an affinity for the 1-sou who is seeking out her missing mother. Future professional mahjong players like Hayari Mizuhara, Harue Akado and others are also featured.
(Source: MangaDex)