 She is first mentioned by Trace after the player has become Champion as a girl looking to catch a powerful Pokémon spotted in Cerulean Cave. After the player has caught Mewtwo in Cerulean Cave and exited the cave, Trace will appear again and mention how the girl looking for Mewtwo had entered the cave earlier. Green can then indeed be found inside Cerulean Cave, at the same spot where Mewtwo was located earlier. When first interacted with, she will toss a Poké Ball at the player, having mistake