Zephaniel was previously an angel who is known to be very obedient to his God, but... He was punished on this earth.

At the beginning of the story, Zephaniel was jealous because humans could have lust, if they were in heaven they would be served by angels.

So, he asked God to change him into a human. Then, Zephaniel came down to earth to experience what it was like to be human.

Then... Over time, Zephaniel became a drunkard. So that he's punished by his God, he will be imprisoned in the world. He reflects while crying at his residence.

"God... Please forgive me..." He cried sobbingly, his heart breaking into pieces.