Yuna is a fairly reserved and serious person, though still very friendly. Ever polite and respectful, Yuna is the epitome of what a "good" Japanese lady should act like. Among other things, she bows a lot. Not to mention that her attire is very Japanese! Japanese people (this may be an overgeneralization) are very private, and Yuna is a good example of this. Even when others try to provoke her, she usually manages to stay calm. She is very temperate, and instead of being rude, Yuna is firm in her rebuttals and doesn't let others bowl over her. For instance, when the summoner Dona snubs her about having so many guardians - "quality over quantity," as she puts it - Yuna comes back and shuts her down. Without being rude. Case in point:

I only have as many guardians as there are people I can trust. I trust them all with my life! To have so many guardians is a joy, and an honor! Even more so than being my father's daughter. Of course, I would never think of questioning your ways, either. So, Lady Dona, I ask of you: please leave us in peace.

Ouch. Take that, Lady Dona. You and your one guardian can just leave them now. Yuna's going to end up repairing the relationship between you and your estranged guardian in FFX-2, so suck it up. (I'm totally serious. You actually do this for that ungrateful snob.)

She is very sensitive, somewhat naïve, and gentle. The first time she performs the sending, she ends up crying. She knows that the people long for the Calm, and she wants to give it to them. Even so, she ultimately despises her decision to destroy her aeons. It was, of course, their only choice, but Yuna still hates that her friends had to sacrifice their lives for everyone else. Her own life she would give willingly, but for others to die because of her choice was unacceptable. She is very caring - her guardians are her friends. "I will not stand by and watch them be hurt."

A simple soul, it doesn't take much for Yuna to be happy - or something as close to happy as she can get. Life in Spira is accordingly simple.