There's definitely more content for tweens. In the book, there are at least 3 kisses (one of which results in the boy getting slapped), an ex-girlfriend who calls Lester "stupid", tatoos, a homeless man that the author insinuates is drunk (younger kids may not notice this), & Will's older sister is a little boy crazy. It's OK for tweens, but I would say 9 is kind of pushing it. This is a great book that I really enjoyed. I like that it's realistic in a way, but unrealistic in other ways. I'm just starting to be a tween & a lot of the content is perfect for my age & older. There's so much to the story that makes for extremely interesting reading. I do think that the content I mentioned above makes the book more interesting.