i know its frustrating but they have to go about this in a very careful way. remember when Shin was talking to the nurse and he asked her not to do anything? thats because he knows it gets worse every time someone "helps" him. I guess his father uses his money to manipulate others into making sure Shin doesn't get removed form the home. So any attempt would only make his father angrier and take it out on Shin. We can see how bad it is now (being starved and beat) and how scared he would be for it to get worse. he would probably be trapped in the house at that point because he couldnt move from being so weak.
I AM NOT SAYING HE SHOULDNT GET HELP i am just saying he knows he cant just go about it in a normal way. he himself has to know if he does anything it has to be 100% successful. I think he is just hoping to make it to graduation so he can move out of the house or go to college to escape most of.
Shin you stupid stupid boy T_T why don't you ask for help? This is so frustrating, if I knew he is being abused I would try to help Shin with or without his consent...