The premise involves a world where devils regularly appear and terrorize people, giving rising to group of exterminators or "devil hunters." One such devil hunter is a real down-on-his-luck guy named Denji who happens to have a devil-dog sidekick with a chainsaw that extends from its face. One day, however, the devil-dog and Denji get intertwined, resulting in Denji taking on the ability to pull a cord from his chest and have chainsaw blades magically appear from his face and hands; a useful tool for a devil hunter.
Yeah, as I said, it's an over-the-top premise. I can find the fun in an over-the-top premise. There's a fine line between it and shock value and I prefer the former as it can be more creative than simply trying to offend someone. If I had any criticism of this first book, it's that it wasn't over-the-top enough! Once the premise is established, Fujimoto starts to build characters and while I can see they'll be interesting down the line, I wanted to see Denji turn in Chainsaw Man more often than he did.
I think there's potential here, and the art is good (Fujimoto's jaggedy lines in action scenes are interesting), but as I'm terrible at finishing any manga series, it's unlikely this is the only one I'll wind up reading.