1st kiss – I don’t want to consider you as sister anymore

I don’t want to consider you as sister anymore
He is her younger brother, although the two have no blood relationship but she always considers him to be her biological brother … can only be brother that’s all. of course he doesn’t want to be like that, but he is also afraid that he will create distance with her more and more far away. If their first meeting in life was not like that, would they have another result? The girl he loves is right in front of his eyes but is like a wind and can’t keep … Can only as younger brother? How must he do to let her know that he can also become a guardian for her whole life?