I actually thought that Battle Royale two was the second part of the same story, and that thy had split the book into two movies, because the book is so massive (I think it´s over 700 pages long). I doubt they got everything into the movie. Wikipedia tld me that they got rd of the epic SUV shootout at the end. Which is !@#$%, because when I was reading it was just thinking "God damn I wann see this on sreen!".