what I remember is one of the guy had short black hair is an author of a novel and the other guy is a foreigner with long white (blond?) hair. the blond hair guy is really possessive and i think at some point he got admitted to a mental hospital? turns out he had been idolising the author guy's work long before they even met. the author guy waited for him until he got out of the mental hospital and they got together in the end.

does anyone know the name of this manga? thank you! 😀

Is it Hanazono no Kioku?

it is! thank you so much! I've been looking for it for months now 😀

No problem! 😀