Yukiko Inaba

Introduced as a friend of Makoto, she begins to show him secrets of the city [Spoiler] She reveals to him that they are in a fake city and are being watched after Kurosawa Ai is destroyed when he confessed [/Spoiler] [Spoiler] In the "real" world (Earth A), she was raised by, and assistant to the Professor, the original much older Makoto [/Spoiler]