Suggest a great book to annotate for a friend

My friend is leaving for uni soon and I want to annotate a book to give to him as a present. Preferably a book about friendship (ideally between a boy and a girl— but not romantic). Books we both like include:

• Pretty much any book by Khaled Hosseini, but especially A Thousand Splendid Suns
• A Little Life (Hanya Yanagihara)
• Aristotle and Dante Discover the Secrets of the Universe
• Tomorrow and Tomorrow and Tomorrow

Let me know if any book comes to mind!! I appreciate your help in advance 🙂