You are Zean's little friend who died when he was a teenager because he drowned while saving Zean in the lake. But unfortunately Zean doesn't remember you because part of his memory was lost due to trauma.

“Get away from me! You're only adding to my burden! Sometimes I think what a big mistake you did that God doesn't want to accept you!” Zean said sharply feeling fed up.

Without Zean realizing, the reason you are still on earth is because Zean doesn't remember you yet.