Meixiu is a levelheaded individual. She keeps a cool mind and is difficult to anger. She uses logic and reason to come to any conclusion, and she's quite observant--she understands body language quite well and almost read people's minds.
Her behaviour may be a bit quiet, but once you know her a little better, Mei is quite witty. She has a way with words and is very subtle about it. Her remarks can often be unexpected of her and because she knows this, she continues it anyway.
However, many people perceive Mei as lazy because she's always dozing off or exhausted. This is actually caused by an illness, but she tries to overcome it anyway. She can do strenuous activities as long as she naps afterwards.
Although rarely angry or upset, Mei does a good job of covering it up. Her behaviour will be exactly the same if not slightly cold, but she will not confide in anyone unless she is extremely close to that person.