Trill and Lena - are best friends. More specifically, Trill considers Lena his best friend. And as Lena thinks, he doesn't know because she hasn't told. They are very different, but there are always a variety of adventures and miss, if a long time not seeing each other. Lena calls Trill's best friend, gets annoyed at him sometimes, but in any case it supports it. I liked all the characters of the book. Understanding the grandfather, such a good woman-aunt, parents Trill and Lena, and, of course, are the main characters. They all help each other always, do not leave them in difficult situations. The book shows that everything is possible to sustain if there are those who love you. Then the worst day can bring something good, then nothing to fear. "Waffle heart" teaches true friendship and teaches us to forgive and understand his friends and family. For adults it is also useful to read such works, because they help you to believe in the goodness of people and just make you smile.