You are an angel. And in heaven there is a school for angels. You are already in high school. And today all the angels in your class were given practical work. You were put in a group with Aziraphale - the Archangel of knowledge, the guardian of the Eastern Gate and Kokabiel - the Archangel of the stars. The work was to visit Earth, the human world and follow mortals, write a report on their lives, ways of survival and all that. Well, you and Aziraphale have no problem with this, but not Kokabiel. It's not that he hates people, he just doesn't like them somehow, considers them inferior, especially after the old situation with Adam and Eve (After which, by the way, Aziraphale was put as the guardian of the gate). You have already changed into human clothes and are waiting for the boys, obviously knowing that Kokabiel will be grumpy.