Okay, wow. This book is seriously awesome. I'm almost afraid to watch the drama now, knowing how different it is.
I zoomed through this book, finishing it in only two days, which is really quick for me, but even though I would do my usual "read a bit and put it down to do something else", it was really hard to stay away for long. I so, so, so wish I could recommend this to everyone, but er...it's not in English. But I do highly recommend it if you can read Japanese!
If you're familiar with the drama, the plot is...really not at all the same. There's a high school boy named Kiritani Shuji, and he takes it upon himself to "produce" a kid who's being bullied and make them popular, but that is really the only connection. Characters in the drama are made up for the drama, including Akira, the other main character in the drama, and characters in the book don't show up at all, except for Shuji, of course. The kid being bullied in the drama is a girl, but in the book it's a boy. I haven't watched the drama yet, but from what I know of it, it's pretty much a totally different story.
So this story. Shuji's life is all an act. He keeps himself at a distance from everyone and, frankly, is kind of sociopathic. During the middle of his second year of high school, they get a new student in their class, a fat, nerdy boy called Kotani Shinta. He writes his name on the chalkboard, 信太, and Shuji at first reads it as Nobuta. Nobuta (野ブタ) can also mean wild pig, so Shuji takes to calling him that (first in his head, then getting everyone to call him that). From the first moment, everyone hates Nobuta. After a while, Nobuta, seeing how popular Shuji is, asks him if he can be his apprentice. Shuji turns him down, but then gets an idea, what if he could be Nobuta's producer, and turn him into someone popular?
Nobuta agrees and most of the book is spent detailing how Shuji makes Nobuta popular. His plans work and he's really pleased with himself for being able to control everyone this way. However, as Nobuta gets more popular, things start falling apart for Shuji. In the end, he pushes away even Mariko, his fake girlfriend, and Nobuta, the only two people who still believe in him. At the end of the book, he transfers to a new school and it's implied that he'll start all over again with his fake personality.
So basically, instead of the feel-good happy ending where everyone learns a lesson, he hasn't learned anything, or rather, the experience just reinforced his belief that he shouldn't let anyone get too close.
(After writing this, I did finally see the drama, and yeah. The drama was total crap compared to the awesomeness of this book. They are pretty much the same in name only.)