This book is from the same series as As Melhores Histórias da Mitologia Nórdica I read earlier this year and as such I had high hopes for it. It was somehow better than the other one.
First of all, it was shorter. It also was made as a single story, from begining to the end, instead of a collection of random stories. I guess my interest in it was also higher because I'm in contact with japanese culture since childhood through various media. I even recongnized some characters, like Amaterasu and Susanoo. It was good to finally have an idea of where they actually came from.
Like the other one, it was divided into two parts: the first one with the main mythological stories and the second with the fable about the 47 ronin. I think that 47 ronin fable was out place in a book about japanese mythology, but it wasn't bad.
I'd recommemend this one for people interested in the subject, but it was not a book I actually enjoyed reading.