[Kazu-kun]

Originally Posted by Utsuro no Hako

I could see a Madoka style ending where someone (Shouma or Himari most likely) uses the diary to fix everything but ends up going off wherever Momoka is.

If it comes to that it would be Himari, I think, since she's already hinted for disappearance in the OP (last shot of the OP). Besides, she's already dead, and I don't think Ikuhara would go for a "resuscitation" ending.

I still think a "no magic" ending is most likely. Maybe it's because of Utena that I think this way. You know,

Spoiler for utena:

everyone and their mother were looking for the power to "revolutionize the world" and in the end there was no such thing. Heck, even the whole deal about "revolutionizing the world" was a totally different thing than what the characters (and the audience) believed.

All that considering, I wouldn't be surprised if the diary doesn't' even do what people (both the characters and the audience) think it does .