Acatalepsy (アカタリプシー)/theories

Who is Akai Onna
Akai Onna, also known as the lady in red, a giant background girl in red seifuku from special path with same girls but different sizes. So who is she can be? There is two theories about her. First one, judging by fact that her path lead to the train she can be friend of Naoto or even girlfriend, who escorted him on a train in a last way. Second theory is, if Naoto is actually a video game character that means Akai Onna can be the owner of Naoto's video game.