Araragi Express is not one of these extremely interesting mangas, and to be quite honest, only the first few chapters are worth reading. The overall manga is not worth your time.
The story revolves around Araragi Riuchi, who is a law student, and because of a crime that he commits, and which he considers is the right thing to do, in his way.
You got a few characters, who accomplish different actions with the main character. You won't find any character developement, even for the main character. I feel like this manga could have been done in a much better way. As I said, you
shouldn't read it. However, if you really want to give it a try, then do so. You will maybe find it better than I did.