Thank you very much, your praise really made my day!
Your ideas are reeaally interestingly close. There's a huge emphasis on the soul so a spirit isn't too far off and fits the bill mostly the same, she isn't normal and she is definitely extraordinary. The world is definitely more of a sentimental one than the normal world as every 'thing' in it holds meaning (I really like the way you put it). And you're very right that she does refer to someone else aside from the PC, directly referencing another person once (which has implications for her part going forward), but it's mostly her talking to someone else.
I had ideas for a bigger version of this story but decided to present them in a much more obscure / open to interpretation way. So I do have lots of things in mind for a continuation :]
-+-+-+-
Extra: In the icon; the title of the game is off-centre, if you remove the 'Mo' part then it fits quite well. In the title screen, the 'Mo' is also a different shade to the rest of the name. The name intentionally has two meanings, that if you read them out; "One soul, no soul" - refer directly to the characters in the story. I won't spoil any more unless you want me to! :>