Think it is a good idea. I like the idea of your demon with a small job, root for the little hell spawn.
Hey, It's me again, I think this is a much better story angle. Not to say that I am anyone worth listening to, but I really really like this idea a bit more and I hope that as you write the story develops--first and foremost--into something you believe you can be proud of. At this point, this new storyline is something I would see at Barnes & Noble and be compelled to read a bit. From there, only the writing (and my wallet) would determine if I bought it. Good luck to you and stay positive. Thanks for hearing our ideas.
This is also a good idea! And to the OP: despite earlier comments, while I said a demon in high school seems a little low right now, I never meant to imply that it was stupid. Just pointing out that with a demonic character coming to earth, High school isn't too much of an exciting place. People grow out of high school-- although it is the perfect time to be a negative influence (or positive )-- and with so many new novels including supernatural catering to the YA, there is a big challenge to make yours stand out. Not matter what you do for any genre I encourage you to write the best story you can