* "Book of Friends" is not a standard, established book. There are many personal journals, friendship books, and even fictional books with that title. We need to know which specific book you're referring to.
* "Nyanko" is a Japanese word meaning "kitten" or "cat." It's not a common name, so it's unlikely to be in a book of names unless the book has a specific theme related to cats.
To help me answer your question, please provide more details:
* What kind of book is "The Book of Friends"? (e.g., personal journal, a book of names, a fictional novel)
* What is the purpose of the book? (e.g., a list of friends' names, a story about friendship, etc.)
With more information, I can try to help you figure out if "nyanko" is in the book.