Kei is one of the two members of the Lovely Angels. She has four different incarnations:
- Kei (light novel) - Kei from the Dirty Pair light novel series.
- Kei (anime) - Kei from the 1980s Dirty Pair television series, Movies and OVAs.
- Kei (comics) - Kei from the comics.
- Kei (flash) - Kei from the Dirty Pair Flash television series.