A very good anime that need to have a 2nd season. It did a great job of building everything up. Has decent story, where you get the usual idiot, selfless protagonist guy trying to help every living thing he finds.
The story sort of has an ending. Yet it leaves a lot of mysteries and plot-knots to be untied. You are left with one view of the characters at the end of anime. However, if you read on about the story in manga or plot summary, you would find out a very different, unexpected, plot twisted view.