Onegai My Melody/WMG

Mana doesn't fear My Melody.
I get a feeling that she isn't afraid of My Melody all this time. The reason why Mana is only pretending to fear her is because she really wanted to be fit with her and the other cute stuff in Mari Land. Somehow, she has managed to tell My Melody this while taking care of her in her house. My Melody begins to understand that and plays along with Mana to be sad about not being liked by her whenever they're in front of Uta and her friends.

Mana is a boy.
Based on the episode where all of the girls at school are turned into boys, Mana is still the same. Must be because she is not really a girl, but a boy all this time.

The entire series is All Just a Dream for Mana.
Okay, have you seen her flashback from episode 8 back when she was a kid? Here goes: she goes into coma after the incident with Harumi. All the cute stuff she interacted in her dream are aspects of herself.
 * Herself = Self
 * Piano = Id
 * My Melody = Super Ego
 * Baku = Ego
 * Kuromi = Shadow Archetype