Different Worlds (Ereri/Riren)

Eren Jaeger lives in the modern world, with all the technology and other 21st century crap. He is one of the biggest fanboys you'll ever find. He loves things ranging from anime to Sherlock to The Fault in Our Stars to the Avengers, he loves anything that is fan-related and appears on Tumblr.
One day while scrolling through his dashboard of Tumblr, Eren finds out about this new book, it's about these giants that attack the last of humanity for all they know. This book is different from the rest, this one literally, I mean LITERALLY, transports you into the book.
Crazy right?
Eren finds himself in this world very different than the one he came from and gets himself in many situations, especially with this guy who's really blunt. After meeting this guy, Eren has feelings towards him, but will he be able to turn the last page of the book? Or will he never close the book forever?
I do not own the Attack on Titan characters and the cover.