The new kid's an active self harmer and only my friend and I know...

First and foremost, befriend him. It's difficult enough transferring schools let alone countries and he needs to find people that he can trust and that will be there for him. Talk to him, get to know him and it's a win-win, you both make a new friend. I'd advise against telling a member of authority. The prying into his life from random strangers and the possible outcome of students finding out is one of the worst things that could happen.

You have to understand that whilst people do self harm for different reasons, often it's not because they want to die. It's used as a means of coping with mental and emotional pain through a method that they have control over and that allows them to 'relax' -as strange as it sounds- it can also become an addiction and can be very difficult to stop for some people. Taking away this form of coping can be extremely dangerous for people that rely on it and if we're talking self harm vs. suicide then obviously the former is preferable although still dangerous and not a healthy method of dealing with emotions.

If you're going to confront this kid then have a plan. Provide him with alternative methods of coping: use a rubber band, exercise, draw, write down your thoughts in a journal, music, watch your favourite program, have a shower. There are also two techniques that have proved to be helpful with stopping: The Butterfly Project and Paper Chain project, so researching those and mentioning them might be useful for him. Also, if you do end up becoming close enough where he's comfortable enough to confide in you then maybe offer to help find him someone to talk to? A school counsellor or nice teacher? They often can't do much but having someone listen to you can take some of the weight off.

I get that this is a lot of burden to put on you. I went through both sides of your situation at 14 too and it's difficult but just be there for him and be his friend, maybe message him on facebook? Telling someone 'stop it' just isn't the way to go.

 

I mean there could be a lot of factors that cause people to start self harming. I'm sure that being uprooted from his home and moving, having no stability, isn't helping. Sexuality can play a stressful part in some peoples lives but if he's accepting of himself then I'm sure that's not the root cause. When I started it was because there were a build up of so many factors that I didn't feel like I knew how to cope with them and it was the only thing that I believed would help, even now, about 8 months clean I have days where I've picked up a blade and remembered that there are other ways. That's why it's important to have alternative methods of providing the same relief. If you do become good friends maybe mention that whenever he feels the need to harm that he could text/skype you and take his mind off it? It's all about finding the coping mechanism that works for the person.

 

Befriend him and if you get close, you can ask him, why he does it. If it's a problem you can solve, help him with it. Unfortunatly, sometimes self harm comes from factors you can't influence. Find out if he wants to quit and if, find him some skills that work.