How can I send a fan letter to a mangaka?

Hello everyone!

I've read the previous questions about how to contact a mangaka and from what I understood, you should send the letter to the publisher of the manga. In my case it would be Kimetsu no Yaiba from Koyoharu Gotouge, but I don't know who is the publisher nor I know how to look for it.

May I ask you for your help in finding the address (and how it should be written) and to teach me how to look for such information?
I would be very grateful to you all.

Thank you in advance! <3

all books have 奥付, which shows author name and publisher name (and publisher's address), in addition to published date, version number, etc.
奥付 corresponds to end roll in movie.

Hi ken, thank you for your help!
Do translated manga have 奥付 too? (Indicating the Japanese information)
I only have the Demon Slayer manga released in Italy

if your book is a genuine one, there should be a description where the publisher have got the license from to publish it in Italy.

Thank you.
It is indeed a genuine book, as for now this is the only publisher in Italy of the manga.
I found a sentence for the copyright that's more or less like this "published in Japan in 2016 by Shueisha Inc., Tokyo". There aren't any other information though.

"Shueisha Inc." is the name that you want to know.
you can find the address in their website.

"how it should be written"
the address and the name should be written, following English manner.
you can use "google translate" or other applications.