Not Sure if my Book Belongs in the YA Category

Hello,

My action adventure/crime fighter book starts off with two characters in their early childhood. They are bullied. Later in the book they become adults. This story does have extreme violence at times. Can I add this story to the YA category with an age restriction of 17. Is that possible? It is just about ready to be published!

Thanks for your feedback. But I forgot to add that one of the characters competes in a Junior Kickboxing Tournament as a teenager. The Other fights a professional kick boxer as a teenager. Both of these events occur within the first 150 pages of the book. After these experiences the characters eventually meet each other become adults and form a security company where they protect entertainers and in the end fight against a villain. I guess what I am saying is the first half of the book could be considered YA while the second half adult. I don't want to lose out on the Young Adult readership but I guess I can't add it to that category if the characters eventually develop into adults later in the book. Do you think Amazon will have an issue if I place my book in the Young Adult category with an age restriction. You do make a good point about the characters being older than 18. I have read that as well. I'm in a bit of dilemma.

Thanks Everyone for your feedback, it clarifies the issue. But now that I know that my book will be best served in the Adult Novel Section I think I need some Beta Readers to determine what genre I should place it in. I understand I need at least 50 posts to request someone to Beta Read my book and that's fine but my book is mostly about bullying/revenge/combat/mma/kickboxing etc. It also has a couple of pretty violent scenes and then a revenge scene that follows up the violent scene. It will be fun discovering which categories to place my book in once I submit it to amazon. I understand that I can submit it up to 7 categories (I'm sure the Beta Readers will tell me). Well thanks to everyone who responded. I have learned a lot in a small amount of time. I also would like to become a Beta Reader as I really enjoy reading other authors work. I appreciate you all for your feedback. I really like this forum. And I apologize if I have been long winded. You folks are awesome.