I’ve been searching Google for a book with absolutely no luck. It was the reading textbook that was used in my kindergarten class in 1985/86. The two characters were Buffy & Mack; a panda and a rabbit.
If anyone has any information on this book (author, publisher, dealer) or if you know where I can actually get my hands on a copy I would be very appreciative.
EDIT: Thanks to Amy, I know that it is called Sun Up.