Kei Nagase (AC2)

Overview:
Kei Nagase, callsign "Edge", is one of Scarface One's two selectable wingmen in Ace Combat 2, alongside John Harvard. She bears an uncanny resemblance to the Kei Nagase from Ace Combat 5, sharing both her name and her callsign, however, it is unlikely that they are the same person, since AC5 ' s Nagase is a rookie pilot, whereas AC2 ' s one is an experienced ace (and AC2 takes place twelve years before AC5). Also, this Nagase has a much higher voice than the one in Ace Combat 5. There is also a civilian named Kei Nagase in AC04, who is unlikely to be related to her, too.

Trivia:
A character named Reiko Nagase, with a notable resemblance to Kei, plays a role in the Ridge Racer series. In Ace Combat 2's details (where she is available to be chosen as your wingman), it is stated she is Reiko's sister.