Kiyosumi High School's one match away from reaching finals at the 71st National High School Mahjong Tournament, and it's up to Saki to bring it home. She's already familiar with how strong Himematsu's Kyoko can be, but her other two opponents, Rinkai's Nelly Virsaladze and Usuzan's Sawaya Shihihara, are downright frightening! Mysterious forces are at work as the semifinals reach their climax...!