Watermelon has released Ch. 9 on their site. Spoilers are in this topic and might not be hidden/tagged so be warned.
As of Chapter 9...
We learn more about Fuwari's past with Rito.
Spoiler
Initially I thought she was the glasses girl, but she isn't. The glasses girl liked Rito, but the other girls convinced Fuwari to ask Rito to meet her (Fuwari) in the back of the school. The glasses girl confesses, but Rito rejects her. The girls made it so that Fuwari tells Rito "It was a joke" and she could not refuse because she always wanted to be a "good girl" in front of everyone. Rito now ignores Fuwari. Fuwari transfers and cryingly says "I'm sorry" to Rito. I guess there was no response because it goes back to the present right after that.
So was Fuwari's name before Hoshino Shizuku? I kind of feel awfully bad for her, but I think the next chapter might delve deeper into the kouhai's past.