A thing that has been bugging me. Feel free to input or correct me

Something that i threw in the thinking pool was "maybe Nami is the center of this". Katie showed up to the book club after a while cause she knew Nami would be there, Nika was a surprise for her. During Nika's therapy sessions Amber tries to sneak Nami in there to get information, She knows Summer is the reason for his state of mind. Sasha also tries to ask about Nami's earing but Ayua interrupts her. We know a "woman" gave her the earing when she was little. But then i thought why now? Why wasn't this happening when they were in high school. Amber and Nojiko know each other its a dead given, but how did Bella or Nami get each others contact info for the school uniform prank? maybe through social media.

I had a theory about Bella's sister like it would be a Kasumi thing from persona 5 but it didn't make sense. But what if Bella wasn't the one being bullied but her sister and an accident caused her to be in a coma, Mila said she apologized but Bella rejected them. She just insults Mila cause she stood up to Melanie. Was that girl Bella's sister or Bella because Mila told Nika what happened before so Nika assumes its Bella. Like i said its a thinking pool its something that's been in my head, maybe I'm completely off the mark. I have some more but I'm waiting on season 2 to connect the dots, I'm hoping for Elena Petrova to show up that'll really clear some of my board.