I've been reading Inside Mari/Boku wa Mari no Naka(Up to date on it now, I think Shuzo Oshimi is going to release 1 more chapter.)
It's been really good, at first I was quite sceptical, but it was certainly worth the read...
I'm bad at explaining stuff, and I don't want to risk spoiling the story, so here is the link to the MAL article about it.