A Story About a Hallucinatory Girl - Ch. 1

[Mithgol]

I have not yet read ahead of this one chapter (and thus the following thought is not a spoiler), but I guess this story is going to have some bad end very similar to xkcd nightmares.

 

[ColorlessBoy]

The basic premise combined with author loving messed-up stories makes me think this could follow a similar route to Saya no Uta.