Going to the same school as the others, Sarena is the one who knows the answer to every question, and does all her homework even when she doesn't have any. Sarena has the uncanny ability to get along with everybody, and even the school bully pretty much leaves her alone. She's also a great medium for Paul and the others to bounce ideas off of, seeing as her advice is greatly valued within the group.

Now not many people are aware, but Sarena is actually a high level blackbelt, and a master of self-defense.  However, she doesn't like to over demonstrate her Karate expertise, out of respect for the tradition and her Sensei.