Reiko Nagase is the official mascot of Namco Bandai's Ridge Racer franchise, and a "Race Queen", basically the motorsport equivalent of a booth babe. Reiko herself, though, is not based on a living person, and is strictly a fictional 2D character.
Reiko was first seen as an unnamed race queen holding countdown cards at the starting line in Ridge Racer. She also appeared in the game's various FMV cutscenes wearing a distinctive red-and-white outfit. She became known as an easter egg character, favorite of the franchise's CG director Kei Yoshimizu.
Reiko gained an official name and identity in Rage Racer (and appeared during the CG intro to Rave Racer), but was given much more prominent exposure during the promotion of R4: Ridge Racer Type 4 and Ridge Racer 64.
She was replaced by a new character "Ai Fukami" for Ridge Racer V's PlayStation 2 debut, but was returned to the role after Ai proved to be less popular. Reiko was mascot of Ridge Racer 6 and Ridge Racer 7, as well as subsequent Ridge Racer franchise incarnations, including the PlayStation Portable Ridge Racers games, Ridge Racer 3D, the Ridge Racer pachislot machine and Ridge Racer Accelerated, an iOS title.
Reiko was also implied to be the mascot for Ridge Racer Unbounded in that game's teaser trailer, however she does not appear in the final game.
Reiko hails from Tokyo, stands 165cm tall (5' 5"), and has a blood type of A. She enjoys swimming, SCUBA diving, driving, and making souffle. Her favorite (Namco Bandai) video games are Pac-Man and We Love Katamari.
Reiko has a younger sister (apparently a twin) named Kei Nagase, who played as a major character in Ace Combat 5: The Unsung War. Kei operated under the callsign "Edge", and was the player character's wingman.
While only officially linked to the Ridge Racer franchise only, Reiko has made appearances in other Namco Bandai games, including as a playable character in Smash Court Tennis 2 and Namco Wonder Classic for the Wonder Swan, and as an unlockable skin in Tales of Phantasia: Nanakiri Dungeon.