The main character was a delinquent boy with superhuman levels of strength. I think that he tried to go to a new high school because he got kicked out of the one he was at for fighting(?) and he has to take care of his younger sister. He gets a call (or something notifies him) that some people have his sister and he goes there and beats them up and leaves with his sister but someone murders the guys he beat up and they found his fingerprints on the murder weapon. As a result he gets arrested and goes to a jail on in island (can’t remember if he got there by boat or plane) and when he is there it look like a classroom and is full of murderers and he is called the “murderer of love” or something similar.
He gets into a fight with some big dude that sits behind him and then breaks the handcuffs that he’s in and throws the big dude into a chalkboard. The 'teacher' walks in and threatens to murder them if they don’t follow the rules but then encourages them to fight. Then the main character declares that he will find a way out, clear his name and help raise his sister.
The main character is seen beating up some guys I think and then he goes home to his sister and somehow later he gets a call that they have his sister and he goes to the place and beats them up and gets his sister and leaves, but someone comes and takes the knife the mc was holding (he was holding it because he took it away from one of the kidnappers) and then killed the guys the mc beat up (there was 3 guys I think), but later he goes home and finds some police or FBI talking to his sister at the door of his house and then he talks to them and then he goes with them to prison but prison for murderers is on a island that is only accessible from boat or plane (the mc took one of those to get to the island) and then he was called the “murderer of love” or something and people say he has a sister complex.
When he gets to the island he is sat in a classroom looking place and everyone there is in shackles(maybe it was just the mc) and the guy behind him was a larger man and started to antagonize the mc and tried to fight him and then the mc grabbed his arm and threw him over his head into the chalkboard and broke the wall to an extent and then the person I think was the teacher walked in and told them that they can fight and encourage each other to try to kill each other( because he thinks they're scum because they murdered people) but he said that he will not stand to be interrupted and will kill anyone that interrupts him or disrupts him when teaching and the big guy goes and sits back down there was also a guy (also a murderer sitting close to the mc) encouraging the fight between the mc and the larger man.
