Rei Mii is a pragmatic, energetic, and occasionally cynical person. She is quite brash and quick to anger, often picking fights (which she has little trouble winning, being able to match even the likes of Zairin in hand-to-hand combat) with people who disagree with her. While she puts on a strong front, she is actually quite emotional at times, especially when the subject is Ra Kan.
Ruuji: The two had a rocky start, but became close over the series. She is often seen taunting Ruuji for being inexperienced in Zoid combat. And while Mii does have some feelings for Ruuji, and is willing to state them to herself, she is never seen acting on them.