Wait what happened at the end? Can somebody please explain
The mother abused mentally, emotionally to him. When he discovered that the 7th reason why he wouldn't go outside was because of the mother and when he saw the mother on top of him and heard everything, he beat her, basically, and then got to jail. Then his brother take declaration and confess everything that the mother was doing to him and the reason of why his brother did what he did, so they can let him outside sooner. And at the final pages it's his brother waiting him "outside" finally. He finally got free and get to go "outside".
The octopus and flower