Satsuki Yatouji

One of the Dragons of earth, a complex and ingenious young woman with utter contempt for humans, and a love for the digital world.

Even though being usually cold and emotionless, she develops feelings for Yuuto.

In Tsubasa Reservoir Chronicle:
In Tokyo, she's one of the seven fighters of the City Hall action. Unlike in X, she studies medicine and is more no-nonsense than apathetic or heartless. She initially receives Syaoran's group with suspicion, but later treats their wounds.