Shino will, in the course of her attempts to find her mother, discover an Awful Truth about her disappearanceSaki, after making it through the prefecturals (the minimum step necessary to see her sister again), has the less than pleasant experience of finding out that Teru is denying having a sister, so it's likely that after a similar point, Shino might find out something similar about her mother, given that her goal is similar to Saki's. The most likely theory is that Shino's mother walked out on her and no longer has any desire to raise or see her daughter again.
Shino's father walked out on her motherShino's mother commented on how her daughter "can't tell good men from bad ones." While this could be a playful jab at her younger brother, it might also explain why Shino's father is not present in his daughter's life- he was a "bad man" whom Shino's mother trusted enough to have his child, but didn't know he would abandon her to raise Shino alone. It's also possible that this is somehow related to Shino's mother's disappearance.
Shino will meet her elementary schoolmates when she participates in the 61st interhigh mahjong nationals.It happened with Shizuno, Ako, Kuro, and Nodoka.
- Confirmed in part. Shino manages to meet up with Rui, but not in an actual match, as Rui gets disqualified early on.
Shino will collapse during or shortly after the finals of the Matsue Children's Mahjong Tournament.She did run 12.5 kilometers nonstop and her fatigue just seemed to have been handwaved right after she told Kanna that she was a little tired.
- Jossed. Shino doesn't seem tired at all after the tournament comes to an end.
Mafuka Kasugai will be exposed as a cheater at some pointShe has the ability to do sleight of hand with mahjong tiles, not unlike Hajime, who cheated in the past and wears chains as a result. And since Mafuka is an adult, a professional and a somewhat famous figure, it's possible that the consequences will be much more severe, likely ending her career. Hayari will likely go through some angst as Mafuka becomes a Broken Pedestal, but ultimately resolve to be the person she thought Mafuka was.
Mafuka's condition is much worse than Hayari thinks, and she's lying to Hayari about itAdults are less than forthcoming about issues like death, and it's possible that when Hayari thinks Mafuka has been transferred, she has actually passed away.