I.O.U. FRIENDSHIP Friendship - having the perfect pal is the best thing ever! Show your friends how much you care. At the back of each book there are sixteen unique Love Hearts[registered] I.O.U.s to fill out and give away to friends and family, or that someone special, as an extra-special gift. It's also packed with vital dos and don'ts, ace quizzes, some golden rules and lots of fascinating facts.