The Guardians are always watching.

This is Waverly, talking to you through this book of sorts. I'm a guardian angel, I take care of kids basically and I watch them till they well die. Guardian angels are as human as humans except once they graduate from a special school they stop growing and their purpose is to take care of humans. Guardian angels are humans who died, you are free from being a guardian angel once you find out how you died. Most people stay as a guardian angel as there isn't much from there on except for being sent into heaven or hell.
There are bad guardian angels, they're called demons, their job is to make sure they ruin human's lives, they all come in different shapes and sizes.
I'm a guardian angel, I hate my job and I have at least taken care of two kids. I'm currently taking a break so I'm just enjoying my time in the middle place where angels, demons and everything in between, spend their time.
Our world is a lot like humans, so we can reproduce, get drunk, grow if wanted, go to jail and do illegal shit.
Personally I would say being a guardian angel is shit but, I think my future might be a little adventurous.