looking for a manga

hi there, i hope sumn can help me. im looking for this manga that i read years ago (specifically the author, but i dont remember their name nor their other mangas except one).

they have very wholesome romance mangas, one of which had two childhood friends, a girl and a boy with the boy (ML) having foreign blood(?) and i think the FL was a little older as she babysat the ML. the ML wants FL to marry him but the FL only wanted to humor him and told him when “he gets bigger” fast forward years later, the ML came back to JP from abroad as a chubby guy as he misunderstood FL and thought she would marry him if he was “fatter” but the FL merely meant when he gets older.

that’s as far as i remember, all i know is that the author has a distinct art style. tyia !