Don't make the mistake I made, of reading all of the written metatext material in the GUIDE before you start playing.
Instead, just start by typing PS 1 to read the first footnote. (Whenever you see footnotes in brackets, e.g. [CAS 1], you can type the text in brackets to read the footnote.)
The first footnote includes a tutorial, allowing you to start playing and familiarize yourself with the characters before you dive into the metatext.
(Unfortunately, some of the metatext implies that you need to read the metatext first, and in particular, that you need to read every page of the metatext just to find out how to read footnotes, to find out how to access the tutorial. IMO, this is a bug in the tutorial, and I hope it gets fixed.)
I, myself, really didn't enjoy this game, because I spent an hour scrutinizing the metatext before engaging with the characters.
But you won't make that mistake. You'll like this game much more than I did, because you read this review.