Just saying the information that will be available in the spoilerish version. Since you will be reading csv files before actual update no point calling it a spoilers then.
I didn't say they are siblings. I said if you change Taichi's mom in Magic Ring, Tomori will be born instead of Taichi and there will be no Chihiro.
Think of it as compass. What you can change about them.
- North - Masumi Hasegawa. Only thing you will be able to decide if she dies there or comes with you.
- West - Masuo Karasuyama (Street Hound). You decided whether he moves on from Junsa to her daughter.
- South - Reita Sakurai. You decide to Izumi's fate. Aoi and Junsa come to your universe if you met Reita once.
- East - Masumi Onizuka. You decided who she falls in love with. Masuo, Aone or Reiji.
Now about other versions.
- Ousam - No significant since he is just a story bit for Aoi Matsuzaka's questline. After that he never appears.
Zombies in Hailey's campaign are effect of a virus.
The ones in Ayako story, turned like that after getting in contact with Merusa's gemstone. They died after that gemstone is destroyed.