@Kraco so just because he doesn't play it's ok to treat him poorly? I don't see in any way how that's justified, he'll survive without the piano it's not a must in his life. He'll probably feel better etc but his life would in no way end if he didn't pursue music on a serious level compared to not playing the piano. If everything that's been depicted happened in reality those friends would have put him in the hospital several times for not doing what they wanted. So why is it okay? Also treating him poorly has shown to be next to or completely inefficient so far. Forceful might help but treating someone poorly is to me never the answer.
@Shinta you talked about the results, I talked about if you break down their actions and look at them that they're dangerously close to bullying, results doesn't absolve that or take it away. But I'd probably be completely fine with all of this if they didn't include all the beatings, the blood thing just makes it worse since it makes them look like they don't care if they hurt him to that point. Again I realize my reaction is over the top and it's for comedy but I don't see the humor in kicking a guy that's already down and suffering from a trauma, especially not a show that seems to go for warm feelings. The contrast is just weird for me and like you said the show doesn't even need them.
Also if we look at the results, nothing they did moved him nor did any of those things I mentioned make him play the piano, they might have stirred something but none of it would have made him take that final step. The only thing that moved him was when Kaori made an honest plea for help. So is that smile and him playing a result of the "bad treatment"? My answer is no, it's a result from that honest plea and his willingness to be there for someone going through something that he has experienced. If you really think it's because of what I found to be bad treatment I'd really like to know how because the only thing I could think of was knowledge of the score.
http://youtu.be/gPPp3zWogfI?t=11m2s an extreme version but kinda illustrates what I mean. Warning the segment is kinda long and might be a bit graphic and uncomfortable or something else that I missed. It's about a guy who had/has a habit to bite his nails so to make him stop his friend starts biting his friends nail and doing all kinds of things to it and messed it up quite bad/sandpaper/smashing it/digging it out with a toothpick in order to make him stop biting his nails. It's ok though because they're friends and he's only doing it to help him. Again it's an extreme example but that's how they come off to me because of the beatings and it kinda ruins it for me which feels like such a shame because I'd probably love the show otherwise.