It's a lovely journey of Rintaro and a cat who wants Rintaro to come with him and saved books. There are four labyrinths with with different book saving cases in each of them. Every chapters give us important messages and lessons.

I listened to the audiobook, and I'm going to say that Sōsuke Natsukawa succeeded building a world that would make the reader drowned in it. It feels like I was there following Rintaro and The Cat's adventure as the third person, experiencing every bits of detail with them, not just as a reader who's currently reading their story. Listening to this book is lovely, heartwarming, and I very much enjoyed every seconds of it.