Story
The weak sumo club of Odachi High School welcomes a new "small" member, Hinomaru Ushio. Everyone thinks he's too small for this sport, where having a "big" and "heavy" body is crucial, until they reveal his past! The goal is to become a yokozuna, the highest rank in sumo wrestling. Fired up high school sumo begins now! (Source: MANGA Plus) Note: - Includes two extra chapters. - Includes the one-shot "Hinomaru Zumou X Kuroko no Basket"
Synopsis via AniList (English).
Preview
From the anime adaptation: Hinomaru Sumo.