If this series has a sequel, it has to take place precisely three years after the end of this one, and Solo has to be a teacher. Because that class would be amazing. (actually, he could teach a music class, or... battle tactics... Perhaps he could work together with Frio in a class all about breaking desks)
The very thought excites me. We could make up new characters for the new class, while our old ones are most likely still there and interactable in some way!
SEQUEL, DEFINTELY SEQUEL.