She is the race queen featured in the Ridge Racer series, as one of the girls holding cards before the start of each race, and appearing in the FMV cutscenes. An unnamed girl resembling Reiko first appeared in the real-time arcade intro for 1995's Rave Racer, but she was officially reintroduced (and named) a year later in Ridge Racer. Whether the Rave Racer girl is supposed to be Reiko is unknown, but Reiko's Ridge Racer 6 outfit bears a resemblance to the Rave Racer one.
In 1998's Ridge Racer Type 4, she was given more prominence, as the opening animation, which used a Kimara Lovelace song, was a short story starring her, and introduced a redesign to her 3D model by Kei Yoshimizu. This is when Namco started giving more exposure to the character, heavily using her image to promote the game.