
Quick answer — Kyouko Tonguu voices Kei in Dirty Pair, Nakamura in Black Magic M-66, Chibi in Demon City Shinjuku.
Kyouko Tonguu voices Kei (Dirty Pair), Nakamura (Black Magic M-66), Chibi (Demon City Shinjuku).
Kei is voiced in Japanese by Kyouko Tonguu.