Geesh, there are some stupid stories in this. Some are nice and interesting, but some are just headdesk-inducing. Anyway, this book alone isn't good for self-study, since you won't have the answering keys, or even a decent explanation of the grammatical constructions. The assignments are mostly just 'conjugate the following verbs as follows', not explaining what they'll mean when conjugated. In other words, you need the answering book or whatever it's called, and a teacher to help you out would be very handy.