I don't think he's 16, Kilus. They're probably more or less the same age, just the chummy dude is...well, chummy. I'd say they are 14.
When I think about it, similar thing happened in my school to one kid from my class when I was sixth grade in elementary (13-14 years old).
The kid who was bullied was a thin, weak dude, as you can imagine. He was bullied by 4-5 guys of similar age, but much stronger and bigger. Poor guy couldn't do a think. He was beaten up a lot, and in the end all those kids got was a detention and lowering the "behaviour score" (stupid thing that measures your actions during a school year, best being 5, and worst being 1. Bastards got 4. During next year, score gets back to 5 again).
Of course, the dude was bullied on until he finished elementary, and from what I hear, those bastards are pretty-much the same. It's just that they're now using knives and guns instead of fists.
If they were taught how to behave properly when they were younger, they wouldn't be like that. Sometimes slapping your kid a few times when they fuck something up is a necessary thing for a good upbringing...and quite effective.