Koukyoushihen Eureka Seven, Houseki no Kuni Recommendations
A flower wishes to be a big tree or a bird flying free but it can’t. No matter what, the flower will always bloom, always bud and always become a fruit for someone else to pluck. The flower cannot change what it is and yet, it is always undergoing change.
Both MCs try hard to change who they are, to save their friends, to improve, to fall in love - without realising that their metamorphosis has already begun.