Both the dramas is focused on a child with leukemia and on his efforts to not let people around them worry.
Both the main lead has been ill since an early age and tenaciously accepts their own situations. I Give My First Love to you is more romantic that A Pledge to God that is more family related.
In both dramas there is an ill child and in both of them the child try his best to not weigh on his family.
In both dramas there are adolescents who fought among a terrible disease and there is a caring family behind them.
In both dramas there is a child caught between two familes and in both dramas the child has leukemia.