Was there any book that you enjoyed writing the most?

Mr. Murakami:
I read one of your books a few years ago, and I haven't stopped since. I love the way you write, and how you surprise me in every page.
I have enjoyed every single one of your books and I want more, I have a few favourites, but I wanted to know yours.
Was there any book that you enjoyed writing the most?  Or a book that you found hard to write? 
If you had the oportunity that I'm having right now to "talk" in some way with any author that you enjoyed reading, who would it be?  and what would you ask? 
Thank you for doing this, I know readers appreciate it.

A die-hard fan from Chile.
(Crazy Cat Lady、女性、20歳、Student)

Thank you for the mail from Chile. I am glad to know that you are enjoying my books. That is great.

I do not have a "favorite" book. I am trying to do my best each time I write a novel or story. So, each book is equally a sincere product from my soul (so I would like to believe, at least).

Sometimes it is hard to keep on writing, but the pleasure overcomes the hardship without fail. So, please enjoy reading my books just as I am enjoying writing them.

I hope you will like my next one.