I'm so confused. Can someone explain this apple part to me?

what exactly don't you understand? Well, here's a short version, if you have any questions, ask. Hades went to hell and now has to pass trials to get to the god there to fight him and kill him. When Hades gets there, he sees lots of children doing hard work and is told that no matter what they do, they will never be able to make the tree bloom and thus cannot grow up. This is supposed to be their punishment for "killing" their parents, for example by giving birth. But the boy who is holding the stone is different. He explained to Hades that he had to hold the stone so that he could pick the apple and the children would grow up. But Hades blackmailed him and forced the stone on him again. At the end you saw that the little girl was his sister from his last life.(づ￣ ³￣)づ

Side note: not a stone it's a whole ass world called mundus that only adults can go to (where the kids are headed after they grow so they can get reincarnated)

Oh yeah . I forgot this part (づ￣ ³￣)づ( thx )