"your past does not define your future" what Josy has done in his past will not define what he does in the future We have no proof (yet) Maya and Josy have not had an easy relationship and it has not been because of them, it has always been a third party who brings it up
What we do know is that the previous summer they had a relationship during a camping trip. (whether it's the "official" start of their relationship or not, it doesn't matter)
They are in a relationship. Maya's father learns about it (we don't know when during the year, but it doesn't seem very important), and prevents them from seeing each other.
For several months / weeks, they do not see each other. The only hope to save their relationship is to end up in college.
Except that doesn't happen. The break is inevitable. This opens the door for the MC (for the two girls by the way).
Josy seems more impulsive. I'm not sure how to express it, she reacts to what she feels right now, forgetting / putting the rest aside. So when she finally gets to college, she has in mind what she was going through with the MC, Maya being a girl with whom she is on the verge of breaking up.
Except seeing and talking to Maya, she remembers or realizes how she feels for her.