Usami is gentle and kindhearted, but also very naive and not very smart. While she is strict about rules and certain other things, it's very easy to trick or persuade her.

All she wants is to foster love, friendship and good manners, emphasized in her catchphrase "love, love!". Because of this, she can even come across overly sweet and annoying. She encourages everyone to live in peace and strengthen their bonds with each other. She is very happy and proud when everyone gets along, and scolds them when they do bad and kindly asks them not to do it again.

Usami talks in a very childish way, sometimes including chu sounds in her speech, most notably replacing the "desu" copula with "dechu" in the original japanese release.

Usami is afraid of violence, fighting and cruelty, considering all of it "a big no-no" - the mere thought frightens her. She also emphasizes the importance of caring for the environment, prohibiting the students from throwing trash anywhere on the island (because she stated if you littered it would trigger an alarm).