Like the other books in this series, 'Leaf' is about the sweeter side of BDSM, about discovery, and about two men meeting and beginning to fall in love. What starts as potential disaster with Leaf being tricked by his brother turns into the best thing that ever happened to him. James, the man who 'buys' his services, has a lot to do with how it turns out, since he is very understanding.
Leaf is not experienced in BDSM, but he has read and heard enough to be curious. There are things that make him cringe, and he feels a sort of obligation to try, but since James encourages him to be honest (such an important part of building trust), he tells the man the truth. A good thing, too! Everything they try is a huge success though, and Leaf slowly gains confidence.
James is an experienced Dom, and though he wanted a rascal like River, he is pretty happy with Leaf's innocence. I think it makes his inner Dom happy to be the first man to try many of the things he wants to do with Leaf. James is very considerate and careful at first, but determined to push as well.
If you like short, hot stories about two men who each find something delightfully unexpected in the other, if you like their activities to be somewhat kinky, and if you're looking for a story with a softer approach to BDSM, you will probably like this short book.