You've used an interesting method to write this one. At the very least, you ought to be commended for your efforts. Out of all the fiction I've read, I can recall only a few documentation-style stories.
There seems to be a pattern to them. They all use the same type of documents. That is, if the story uses letters, it uses letters to tell the story. Or, if it uses news articles, it uses news articles all the way (One of my favourites of this type of stories happens to use news articles. Really wish I could find it again) They don't change format, such as going from news to personal journals.
Be warned though, it's too easy to trip up while writting like this. In fact, I think you might be slipping already.
I suggest trying to change Akane's journal entry and the transcript into news articles as well. The journal could be a news report on the new management of Ucchan's, and the transcript could be a statement from the police. 
You're fine so far, don't screw up!