Character Analysis
Even though they've been best friends since, well, forever, Mia and Jenna still have a few smack-downs in the book. Jenna gets pretty upset with Mia for not sharing her synesthesia with her—after all, secrets aren't supposed to be kept from your best friend. Jenna doesn't quite put it so gently, though:
"Maybe you don't know what a best friend is […] I don't understand why you didn't tell me in third grade. Or fourth grade. Or seventh. It's always been you and me against the world. I'll bet there are lots of things you don't bother to tell me." (4.173)
Ouch. To be clear, Jenna only knows about Mia's synesthesia because Mia's decided to tell her; it's not like she heard it from someone else. And telling Jenna her biggest secret is a really big deal for Mia, so when her friend reacts this way, it cuts deep.
Eventually, though, Mia and Jenna make up, and realize they need to be there for each other. The two of them are solid and a little something like seeing colors everywhere isn't going to change that. Just as Mia comes to understand that she can have friends who aren't synesthetes, Jenna realizes that Mia can have her synesthete friends and still be besties with her.
By the end of the novel, Mia and Jenna even have new friendship bracelets to show off their renewed friendship. We don't get to hear much about how Jenna feels about all this, since the book is just from Mia's perspective, but when Jenna shows up with new friendship bracelets and the two of them hug it out, it's clear that Jenna wants them to get back to being besties just as much as Mia does. That's how it is with friends like Jenna and Mia: These two PIC—partners in crime—aren't going anywhere.