Attention: English is not my native language, so it's little complicated for me to write sentences in English. Though I can understand you all very well. So, be aware of bad English moment in this wall of text.
Okay, but why are there so many versions of Maya? Like, usual Maya, Long Maya, Moyo and that one Maya with numbers instead of name (not long one).
There are two possibilities for the various Mayas.
1) Aside from the actual student named Maya, they're all psychological constructs in Akira's head. Long Maya appears to be middle aged, and represents his desire to grow old with her. Moyo is a dessicated corpse, and represents his fear of her dying. Numbers Maya (the numbers spell out AmIOkay in hexidecimal, btw) I'm not sure about (I'd need to replay the happy scenes), and the warehouse full of Hanging Mayas would indicates that she exists in his every thought. This explanation would require all the various gods to be metaphorical concepts in Akira's head rather than literal beings.
2) If they're literal beings -- Maya tells the story of the celestial princess and the mortal she falls in love with on her birthday date with Akira. This might be a literal story. She, Long Maya, and Moyo might form a trinity, and she might have abandoned her post to be with Akira. That's why her past prior to meeting Akira is so mysterious to everyone. When she did this, she was a child, so we had child, mother, and crone (similar to the Greek Fates), and now her post is empty (the empty chair in the talk show segment). This gives very strong Wings of Desire (German film) and City of Angels (American remake of wings of Desire) vibes, where an angel falls to earth to be someone they've fallen in love with. AmIOkay appears to be being punished by the Angels for something, possibly this abandonment of her post, and the warehouse of Mayas could mean that the Mayas are trying to figure out a way to create a replacement for her.
